Russel wants to add some styling to a document he typed. he starts with red text and is debating between a green or a black background. why is red text on a green shaded area the less acceptable choice?

red text is considered hard to read.
there is not enough contrast between red and green.
green shading does not exist.
these colors contrast too much and are difficult to read.

Explanation:

In writing activities there are rules to write properly. Some of those rules are to improve the sense of a text, but another are to improve the way people perceive the text, which as important as the semantic.

Moreover, Russel typed a document and he's deciding what colour should the text and background. A red tex is not quite a good choice because it's actually hard do read, that's why we tend to chose black our less highlight colours. Actually, red, green, yellow, they are colours to highlight portions of text, in case you want to focus in an specific part.