[New-bugs-announce] [issue38917] Color setting doesn't work in tkinter

[Acid Ascorbic]

New submission from Acid Ascorbic <ascorbic.acid.test2 at gmail.com>:

It is impossible to set colors properly in Treeview.
Python behavior is different between versions 3.6.2 and 3.7.3/3.8.0.
Origin: https://stackoverflow.com/questions/57634982/can-i-change-the-foreground-color-of-a-single-column-in-python-treeview/59047842
Example 1:

from tkinter import ttk
import tkinter as tk

root = tk.Tk()
tree = ttk.Treeview(root)
c = tree.insert('', 'end', text='This is critical message', tags='critical')
tree.insert(c, 'end', text='This is child of critical message', tags='critical')
for i in range(5):
    tree.insert('', 'end', text='This is non-critical message')
tree.tag_configure('critical', background='red', foreground="black")
tree.pack()
root.mainloop()

Example 2:

import tkinter as tk
from tkinter import ttk

root = tk.Tk()
style = ttk.Style(root)
style.theme_use("clam")
style.configure("Treeview", background="black",
                fieldbackground="black", foreground="white")
tree = ttk.Treeview(root)
tree.insert("", 0, "item", text="item")
tree.pack()
root.mainloop()

----------
components: Tkinter
messages: 357501
nosy: Acid Ascorbic
priority: normal
severity: normal
status: open
title: Color setting doesn't work in tkinter
type: behavior
versions: Python 3.7, Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue38917>
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