Nature of issue?

• Found a bug

Details about the bug:

Hi @catarak I have run into this as well, here is a screenshot of how text looks in the Preview window in Dark mode, but in High Contrast mode it is similar, defaulting to black text on a very dark background:
image
Here's an example of a sketch that displays this issue: https://editor.p5js.org/ml5/sketches/XCFPKqIKrt

Originally posted by @leemark in #1400 (comment)

@catarak: I think the issue here is that the iframe should have a default background color of white, as is the norm for websites.