A stunning theme for ttk based on Microsoft's Sun Valley visual style

For the documentation see the documentation!

I wanted to make usage of the theme very simple, so the theme setting is handled by a separate tcl script. This way whether you want to use a dark or light theme, you need to import just a single file. The other thing that makes this a good solution is that normally switching between light and dark theme is not entirely perfect, and the colors are incorrect.

# Just simply import the sun-valley.tcl file
widget.tk.call("source", "sun-valley.tcl")

# Then set the theme you want with the set_theme procedure
widget.tk.call("set_theme", "light")
# or
widget.tk.call("set_theme", "dark")

# Just simply import the sun-valley.tcl file
source sun-valley.tcl

# Then set the theme you want with the set_theme procedure
set_theme light
# or
set_theme dark

Normally changing between themes isn't that easy, because then the colors aren't correct. See this Stackoverflow question. However, with my current solution, you can change theme at any time, without any color issues.

import tkinter as tk
from tkinter import ttk

root = tk.Tk()

# Pack a big frame so, it behaves like the window background
big_frame = ttk.Frame(root)
big_frame.pack(fill="both", expand=True)

# Set the initial theme
root.tk.call("source", "sun-valley.tcl")
root.tk.call("set_theme", "light")

def change_theme():
    # NOTE: The theme's real name is sun-valley-<mode>
    if root.tk.call("ttk::style", "theme", "use") == "sun-valley-dark":
        # Set light theme
        root.tk.call("set_theme", "light")
    else:
        # Set dark theme
        root.tk.call("set_theme", "dark")

# Remember, you have to use ttk widgets
button = ttk.Button(big_frame, text="Change theme!", command=change_theme)
button.pack()

root.mainloop()

# You don't need 8.6 if you use the gif version
package require Tk 8.6
source "sun-valley.tcl"

set_theme light

# Pack a big frame so, it behaves like the window background
ttk::frame .big_frame
pack .big_frame -fill both -expand 1

proc changeTheme {} {
    # NOTE: The theme's real name is sun-valley-<mode>
    if {[ttk::style theme use] == "sun-valley-dark"} {
        # Set light theme
        set_theme light
    } else {
        # Set dark theme
        set_theme dark
    }
}

ttk::button .big_frame.button -text "Change theme!" -command changeTheme
pack .big_frame.button

• Tk isn't really good at displaying png images, so if your program is laggy with the theme, please check out the gif-based branch!
• When you change the theme, and your app has a treeview, the window resizes. This is a quite strange bug that applies to all ttk themes.

I made a separate repo for the examples: Sun-Valley-ttk-examples. Be sure to star and watch it because I will make more examples, with awesome tips and tricks!!

Check out my other themes!

• Azure ttk theme
• Forest ttk theme