Use a less red-ish color for the new prompt and non-error colorized traceback text

[treyhunner]

Bug report

Bug description:

I noticed that the magenta color used by the new REPL and within the non-error text in the new colorized tracebacks in 3.13 looks quite a bit like an error-related color in some popular color schemes.

Here's an image which shows how an error message displays in a few fairly popular terminal color schemes.

I've included both "bold as bright" and not.
Some terminal emulators enable that setting by default while others do not.

Here are 3 more images showing how the prompt and error messages would display if cyan, blue, or green were used instead of magenta.

A script I used to help generate those images

I couldn't find data on which color schemes are the most widely used, so I took my best guesses from a bit of research.
From the schemes I looked at (Dracula, Nord, Solarized Dark/Light, Gruvbox Dark/Light) I think Cyan, Blue, or Green would look the least like red.

I don't want to start a debate over what color to paint the bike shed, but I think the closeness of the magenta and red colors are important enough to discuss before 3.13.0 lands.

CPython versions tested on:

3.13, CPython main branch

Operating systems tested on:

Linux

[nineteendo]

Hmm, sounds more like an enhancement than a bug.

[hugovk]

Regarding bug/feature, I think this is something we can tweak during beta, so let's keep the bug label.

I like the suggestion. We could keep the exception name (ZeroDivisionError) magenta/red-ish.

For example compare GitHub's pytb highlighter:

>>> 4 / 0
Traceback (most recent call last):
  File "<python-input-0>", line 1, in <module>
    4 / 0
    ~~^~~
ZeroDivisionError: division by zero

I think Pygments does something similar.

[treyhunner]

I like the suggestion. We could keep the exception name (ZeroDivisionError) magenta/red-ish.

I agree that the exception name, and even the exception message, in magenta or red seems very appropriate.