The answer is that you cannot do what you want with Idle as it is.
When running Python code with Idle, programmatically changing the display color of stdout text output is not possible for the following reasons. The Idle Shell and Editor windows contain tkinter Text widgets that serve as proxies for text widgets in the tcl/tk gui framework. Statements at a Shell prompt or code in an edit window are run in a separate process. Idle captures strings sent to stdout and stderr, inserts the strings into the text widget, and tells tk to color the text blue or red (or whatever you choose in Options -> Configure Idle -> Highlighting).
Importing textcolor, colorama, or any other module in your code can change the strings sent to stdout. But they do not change how Idle code handles the string when displaying it in a Text widget. Neither Idle nor tkinter nor tk interpret the text. On Windows, print('\033') and
print('\x1b')` display a left arrow. (When copied to an SO Answer edit box, ESC shows as a square with 0, 0, 1, B. When the answer is displayed, ESC is ignored and nothing shows.)
I have in mind adding an option to Idle to run editor code in a console window, with Idle not involved. Another idea is a Text subclass that would interpret ANSI codes, including color codes, before inserting text. The first will be pretty easy; the second will take more work; both would be useful in different situations, and both are in the future.