[IDEA-257985] Update Darcula python syntax highlighting

[ceddy4395]

Fixes https://youtrack.jetbrains.com/issue/IDEA-257985

Due to the potential confusion between error highlighting and keyword argument highlighting for python in the Darcula theme. This colour has been updated from #AA4926 to #34B8A7 in order to have a better contrast.

Screenshot

[east825]

@ceddy4395 Hi! Sorry, it's taking that long to process. Changing some default color for all the users is not a simple undertaking for us, even though I agree that the current color might seem falsely alarming. Another problem is that other languages featuring a similar syntactic concept, in particular Kotlin and PHP, use another color in their scheme for that. Out UI team is evaluating options for unifying all of these. We're most likely to change the color but not necessarily to the one you suggested, and already in 2021.2 as we're past the feature freeze of 2021.1 by now. I'll post the results here once we settle down.