[mmmkkaaayy]

If you haven't before, I'd recommending giving Intellij's semantic highlight a look: https://blog.jetbrains.com/pycharm/2017/01/make-sense-of-you...

Every variable name is assigned its own color, so you can track the data dependencies in your function using color. Similar to what the author suggests as "Type Highlighting"

Some might consider it distracting/overstimulating, but I find it both useful and it makes the code look a bit more 'artistic'.

[lstamour]

Many IDEs, IntelliJ and Visual Studio Code among them, also have plugins for "Rainbow brackets" (the ability to use different colours for different pairs of open and close brackets). WebStorm takes this a step farther and clearly highlights open and close tags in HTML, etc., if I recall correctly.

[account42]

KDevelop had this for a long time and I agree it is useful.