diff --git a/coretk/coretk/dialogs/linkconfig.py b/coretk/coretk/dialogs/linkconfig.py
index bd0a9207..9a2008ab 100644
--- a/coretk/coretk/dialogs/linkconfig.py
+++ b/coretk/coretk/dialogs/linkconfig.py
@@ -5,12 +5,14 @@ import logging
 import tkinter as tk
 from tkinter import ttk
 
+from coretk.dialogs.colorpicker import ColorPicker
 from coretk.dialogs.dialog import Dialog
+from coretk.themes import PADX, PADY
 
 
 class LinkConfiguration(Dialog):
     def __init__(self, master, app, edge):
-        super().__init__(master, app, "link configuration", modal=True)
+        super().__init__(master, app, "Link Configuration", modal=True)
         self.app = app
         self.edge = edge
         self.is_symmetric = True
@@ -19,19 +21,20 @@ class LinkConfiguration(Dialog):
         else:
             self.symmetry_var = tk.StringVar(value="<<")
 
-        self.bandwidth = tk.DoubleVar()
-        self.delay = tk.DoubleVar()
-        self.jitter = tk.DoubleVar()
-        self.loss = tk.DoubleVar()
-        self.duplicate = tk.DoubleVar()
+        self.bandwidth = tk.StringVar()
+        self.delay = tk.StringVar()
+        self.jitter = tk.StringVar()
+        self.loss = tk.StringVar()
+        self.duplicate = tk.StringVar()
         self.color = tk.StringVar(value="#000000")
+        self.color_button = None
         self.width = tk.DoubleVar()
 
-        self.down_bandwidth = tk.DoubleVar()
-        self.down_delay = tk.DoubleVar()
-        self.down_jitter = tk.DoubleVar()
-        self.down_loss = tk.DoubleVar()
-        self.down_duplicate = tk.DoubleVar()
+        self.down_bandwidth = tk.IntVar(value="")
+        self.down_delay = tk.IntVar(value="")
+        self.down_jitter = tk.IntVar(value="")
+        self.down_loss = tk.DoubleVar(value="")
+        self.down_duplicate = tk.IntVar(value="")
 
         self.load_link_config()
         self.symmetric_frame = None
@@ -44,17 +47,16 @@ class LinkConfiguration(Dialog):
         source_name = self.app.canvas.nodes[self.edge.src].core_node.name
         dest_name = self.app.canvas.nodes[self.edge.dst].core_node.name
         label = ttk.Label(
-            self.top,
-            text="Link from %s to %s" % (source_name, dest_name),
-            anchor=tk.CENTER,
+            self.top, text=f"Link from {source_name} to {dest_name}", anchor=tk.CENTER
         )
-        label.grid(row=0, column=0, sticky="nsew")
+        label.grid(row=0, column=0, sticky="ew", pady=PADY)
+
         frame = ttk.Frame(self.top)
         frame.columnconfigure(0, weight=1)
         frame.columnconfigure(1, weight=1)
-        frame.grid(row=1, column=0, sticky="nsew")
-        button = ttk.Button(frame, text="unlimited")
-        button.grid(row=0, column=0, sticky="nsew")
+        frame.grid(row=1, column=0, sticky="ew", pady=PADY)
+        button = ttk.Button(frame, text="Unlimited")
+        button.grid(row=0, column=0, sticky="ew", padx=PADX)
         if self.is_symmetric:
             button = ttk.Button(
                 frame, textvariable=self.symmetry_var, command=self.change_symmetry
@@ -63,128 +65,185 @@ class LinkConfiguration(Dialog):
             button = ttk.Button(
                 frame, textvariable=self.symmetry_var, command=self.change_symmetry
             )
-        button.grid(row=0, column=1, sticky="nsew")
+        button.grid(row=0, column=1, sticky="ew")
 
         if self.is_symmetric:
             self.symmetric_frame = self.get_frame()
-            self.symmetric_frame.grid(row=2, column=0, sticky="nsew")
+            self.symmetric_frame.grid(row=2, column=0, sticky="ew", pady=PADY)
         else:
             self.asymmetric_frame = self.get_frame()
-            self.asymmetric_frame.grid(row=2, column=0, sticky="nsew")
+            self.asymmetric_frame.grid(row=2, column=0, sticky="ew", pady=PADY)
+
+        self.draw_spacer(row=3)
 
         frame = ttk.Frame(self.top)
         frame.columnconfigure(0, weight=1)
         frame.columnconfigure(1, weight=1)
-        frame.grid(row=3, column=0, sticky="nsew")
-
-        button = ttk.Button(frame, text="Apply", command=self.apply)
-        button.grid(row=0, column=0, sticky="nsew")
+        frame.grid(row=4, column=0, sticky="ew")
+        button = ttk.Button(frame, text="Apply", command=self.click_apply)
+        button.grid(row=0, column=0, sticky="ew", padx=PADX)
         button = ttk.Button(frame, text="Cancel", command=self.destroy)
-        button.grid(row=0, column=1, sticky="nsew")
+        button.grid(row=0, column=1, sticky="ew")
 
     def get_frame(self):
-        main_frame = ttk.Frame(self.top)
-        main_frame.columnconfigure(0, weight=1)
+        frame = ttk.Frame(self.top)
+        frame.columnconfigure(1, weight=1)
         if self.is_symmetric:
-            label_name = "Symmetric link effects: "
+            label_name = "Symmetric Link Effects"
         else:
-            label_name = "Asymmetric effects: downstream / upstream "
+            label_name = "Asymmetric Effects: Downstream / Upstream "
         row = 0
-        label = ttk.Label(main_frame, text=label_name, anchor=tk.CENTER)
-        label.grid(row=row, column=0, sticky="nsew")
+        label = ttk.Label(frame, text=label_name, anchor=tk.CENTER)
+        label.grid(row=row, column=0, columnspan=2, sticky="ew", pady=PADY)
         row = row + 1
 
-        frame = ttk.Frame(main_frame)
-        frame.columnconfigure(0, weight=1)
-        frame.columnconfigure(1, weight=4)
-        frame.grid(row=row, column=0, sticky="nsew")
-        label = ttk.Label(frame, text="Bandwidth (bps): ")
-        label.grid(row=0, column=0, sticky="nsew")
-        entry = ttk.Entry(frame, textvariable=self.bandwidth)
-        entry.grid(row=0, column=1, sticky="nsew")
+        label = ttk.Label(frame, text="Bandwidth (bps)")
+        label.grid(row=row, column=0, sticky="ew")
+        entry = ttk.Entry(
+            frame,
+            textvariable=self.bandwidth,
+            validate="key",
+            validatecommand=(self.app.validation.positive_int, "%P"),
+        )
+        entry.grid(row=row, column=1, sticky="ew", pady=PADY)
         if not self.is_symmetric:
-            entry = ttk.Entry(frame, textvariable=self.down_bandwidth)
-            entry.grid(row=0, column=2, sticky="nsew")
-
+            entry = ttk.Entry(
+                frame,
+                textvariable=self.down_bandwidth,
+                validate="key",
+                validatecommand=(self.app.validation.positive_int, "%P"),
+            )
+            entry.grid(row=row, column=2, sticky="nsew")
         row = row + 1
 
-        frame = ttk.Frame(main_frame)
-        frame.columnconfigure(0, weight=1)
-        frame.columnconfigure(1, weight=4)
-        frame.grid(row=row, column=0, sticky="nsew")
-        label = ttk.Label(frame, text="Delay (us): ")
-        label.grid(row=0, column=0, sticky="nsew")
-        entry = ttk.Entry(frame, textvariable=self.delay)
-        entry.grid(row=0, column=1, sticky="nsew")
+        label = ttk.Label(frame, text="Delay (us)")
+        label.grid(row=row, column=0, sticky="ew")
+        entry = ttk.Entry(
+            frame,
+            textvariable=self.delay,
+            validate="key",
+            validatecommand=(self.app.validation.positive_int, "%P"),
+        )
+        entry.grid(row=row, column=1, sticky="ew", pady=PADY)
         if not self.is_symmetric:
-            entry = ttk.Entry(frame, textvariable=self.down_delay)
-            entry.grid(row=0, column=2, sticky="nsew")
+            entry = ttk.Entry(
+                frame,
+                textvariable=self.down_delay,
+                validate="key",
+                validatecommand=(self.app.validation.positive_int, "%P"),
+            )
+            entry.grid(row=row, column=2, sticky="ew")
         row = row + 1
 
-        frame = ttk.Frame(main_frame)
-        frame.columnconfigure(0, weight=1)
-        frame.columnconfigure(1, weight=4)
-        frame.grid(row=row, column=0, sticky="nsew")
-        label = ttk.Label(frame, text="Jitter (us): ")
-        label.grid(row=0, column=0, sticky="nsew")
-        entry = ttk.Entry(frame, textvariable=self.jitter)
-        entry.grid(row=0, column=1, sticky="nsew")
+        label = ttk.Label(frame, text="Jitter (us)")
+        label.grid(row=row, column=0, sticky="ew")
+        entry = ttk.Entry(
+            frame,
+            textvariable=self.jitter,
+            validate="key",
+            validatecommand=(self.app.validation.positive_int, "%P"),
+        )
+        entry.grid(row=row, column=1, sticky="ew", pady=PADY)
         if not self.is_symmetric:
-            entry = ttk.Entry(frame, textvariable=self.down_jitter)
-            entry.grid(row=0, column=2, sticky="nsew")
+            entry = ttk.Entry(
+                frame,
+                textvariable=self.down_jitter,
+                validate="key",
+                validatecommand=(self.app.validation.positive_int, "%P"),
+            )
+            entry.grid(row=row, column=2, sticky="ew")
         row = row + 1
 
-        frame = ttk.Frame(main_frame)
-        frame.columnconfigure(0, weight=1)
-        frame.columnconfigure(1, weight=4)
-        frame.grid(row=row, column=0, sticky="nsew")
-        label = ttk.Label(frame, text="Loss (%): ")
-        label.grid(row=0, column=0, sticky="nsew")
-        entry = ttk.Entry(frame, textvariable=self.loss)
-        entry.grid(row=0, column=1, sticky="nsew")
+        label = ttk.Label(frame, text="Loss (%)")
+        label.grid(row=row, column=0, sticky="ew")
+        entry = ttk.Entry(
+            frame,
+            textvariable=self.loss,
+            validate="key",
+            validatecommand=(self.app.validation.positive_float, "%P"),
+        )
+        entry.grid(row=row, column=1, sticky="ew", pady=PADY)
         if not self.is_symmetric:
-            entry = ttk.Entry(frame, textvariable=self.down_loss)
-            entry.grid(row=0, column=1, sticky="nsew")
+            entry = ttk.Entry(
+                frame,
+                textvariable=self.down_loss,
+                validate="key",
+                validatecommand=(self.app.validation.positive_float, "%P"),
+            )
+            entry.grid(row=row, column=2, sticky="ew")
         row = row + 1
 
-        frame = ttk.Frame(main_frame)
-        frame.columnconfigure(0, weight=1)
-        frame.columnconfigure(1, weight=4)
-        frame.grid(row=row, column=0, sticky="nsew")
-        label = ttk.Label(frame, text="Duplicate (%): ")
-        label.grid(row=0, column=0, sticky="nsew")
-        entry = ttk.Entry(frame, textvariable=self.duplicate)
-        entry.grid(row=0, column=1, sticky="nsew")
+        label = ttk.Label(frame, text="Duplicate (%)")
+        label.grid(row=row, column=0, sticky="ew")
+        entry = ttk.Entry(
+            frame,
+            textvariable=self.duplicate,
+            validate="key",
+            validatecommand=(self.app.validation.positive_int, "%P"),
+        )
+        entry.grid(row=row, column=1, sticky="ew", pady=PADY)
         if not self.is_symmetric:
-            entry = ttk.Entry(frame, textvariable=self.down_duplicate)
-            entry.grid(row=0, column=1, sticky="nsew")
+            entry = ttk.Entry(
+                frame,
+                textvariable=self.down_duplicate,
+                validate="key",
+                validatecommand=(self.app.validation.positive_int, "%P"),
+            )
+            entry.grid(row=row, column=2, sticky="ew")
         row = row + 1
 
-        frame = ttk.Frame(main_frame)
-        frame.columnconfigure(0, weight=1)
-        frame.columnconfigure(1, weight=4)
-        frame.grid(row=row, column=0, sticky="nsew")
-        label = ttk.Label(frame, text="Color: ")
-        label.grid(row=0, column=0, sticky="nsew")
-        button = ttk.Button(frame, textvariable=self.color)
-        button.grid(row=0, column=1, sticky="nsew")
+        label = ttk.Label(frame, text="Color")
+        label.grid(row=row, column=0, sticky="ew")
+        self.color_button = tk.Button(
+            frame,
+            textvariable=self.color,
+            background=self.color.get(),
+            bd=0,
+            relief=tk.FLAT,
+            highlightthickness=0,
+            command=self.click_color,
+        )
+        self.color_button.grid(row=row, column=1, sticky="ew", pady=PADY)
         row = row + 1
 
-        frame = ttk.Frame(main_frame)
-        frame.columnconfigure(0, weight=1)
-        frame.columnconfigure(1, weight=4)
-        frame.grid(row=row, column=0, sticky="nsew")
-        label = ttk.Label(frame, text="Width: ")
-        label.grid(row=0, column=0, sticky="nsew")
-        entry = ttk.Entry(frame, textvariable=self.width)
-        entry.grid(row=0, column=1, sticky="nsew")
+        label = ttk.Label(frame, text="Width")
+        label.grid(row=row, column=0, sticky="ew")
+        entry = ttk.Entry(
+            frame,
+            textvariable=self.width,
+            validate="key",
+            validatecommand=(self.app.validation.positive_float, "%P"),
+        )
+        entry.grid(row=row, column=1, sticky="ew", pady=PADY)
 
-        return main_frame
+        return frame
 
-    def apply(self):
+    def click_color(self):
+        dialog = ColorPicker(self, self.app, self.color.get())
+        color = dialog.askcolor()
+        self.color.set(color)
+        self.color_button.config(background=color)
+
+    def click_apply(self):
         logging.debug("click apply")
-        width = self.width.get()
-        self.app.canvas.itemconfigure(self.edge.id, width=width)
+        self.app.canvas.itemconfigure(self.edge.id, width=self.width.get())
+        self.app.canvas.itemconfigure(self.edge.id, fill=self.color.get())
+        link = self.edge.link_info.link
+        bandwidth = self.bandwidth.get()
+        if bandwidth != "":
+            link.options.bandwidth = int(bandwidth)
+        jitter = self.jitter.get()
+        if jitter != "":
+            link.options.jitter = int(jitter)
+        delay = self.delay.get()
+        if delay != "":
+            link.options.delay = int(delay)
+        duplicate = self.duplicate.get()
+        if duplicate != "":
+            link.options.dup = int(duplicate)
+        loss = self.loss.get()
+        if loss != "":
+            link.options.per = float(loss)
         self.destroy()
 
     def change_symmetry(self):
@@ -212,6 +271,13 @@ class LinkConfiguration(Dialog):
         :return: nothing
         """
         width = self.app.canvas.itemcget(self.edge.id, "width")
-        # color = self.app.canvas.itemcget(self.edge.id, "fill")
         self.width.set(width)
-        # self.color
+        color = self.app.canvas.itemcget(self.edge.id, "fill")
+        self.color.set(color)
+        link = self.edge.link_info.link
+        if link.HasField("options"):
+            self.bandwidth.set(str(link.options.bandwidth))
+            self.jitter.set(str(link.options.jitter))
+            self.duplicate.set(str(link.options.dup))
+            self.loss.set(str(link.options.per))
+            self.delay.set(str(link.options.delay))