The typography tools that IDEs use for syntax highlighting are bold, italic, and color, which all reduce legibility. That's fine for keywords - I never need to

The typography tools that IDEs use for syntax highlighting are bold, italic, and color, which all reduce legibility. That's fine for keywords - I never need to distinguish between if and lf at a glance - but muddy for the primary content of your code (functions, variables, math symbols, comments). If you wanted to emphasize something while increasing legibility, you'd need to change the font size, which is not commonly supported by an IDE. Shrunken keywords might work. Not in conjunction with fixed width fonts, though.