Partially based on my Azure theme

How to use

Python / tkinter

To use the theme just import the forest-light.tcl, or the forest-dark.tcl file, and call the theme_use method to set the theme:

# Import the tcl file
root.tk.call('source', 'forest-light.tcl / forest-dark.tcl')
# Set the theme with the theme_use method
ttk.Style().theme_use('forest-light / forest-dark')

Tcl / tk

To use the theme just import the forest-light.tcl, or the forest-dark.tcl file, and call the theme use method to set the theme:

# Import the tcl file
source "forest-light.tcl / forest-dark.tcl"
# Set theme using the theme use method
ttk::style theme use forest-light / forest-dark

New style elements

The Forest theme similar to my Azure theme has some new widget styles, such as an accent button, toggle switch, toggle button and card. You can apply these with the style option.

If you need a highlighted button, use Accent.TButton:

button = ttk.Button(root, text='Accent button', style='Accent.TButton', command=callback)

To create a toggle button you need a checkbutton, to which you can apply the ToggleButton style:

togglebutton = ttk.Checkbutton(root, text='Toggle button', style='ToggleButton', variable=var)

The use of switches is becoming more common these days, so this theme has a Switch style, that can be applied to checkbuttons:

switch = ttk.Checkbutton(root, text='Switch', style='Switch', variable=var)

If you only want a border around your widgets, not an entire LabelFrame then apply the Card style to a Frame:

card = ttk.Frame(root, style='Card', padding=(5, 6, 7, 8))

A short example

for Python...

import tkinter as tk
from tkinter import ttk
root = tk.Tk()
# Import the tcl file
root.tk.call('source', 'forest-dark.tcl')
# Set the theme with the theme_use method
ttk.Style().theme_use('forest-dark')
# A themed (ttk) button
button = ttk.Button(root, text="I'm a themed button")
button.pack(pady=20)
root.mainloop()

...and for Tcl

package require Tk 8.6
# Import the tcl file
source "forest-dark.tcl"
# Set theme using the theme use method
ttk::style theme use forest-dark
# A themed (ttk) button
ttk::button .button -text "I'm a themed button"
pack .button -pady 20