All elements in a document need to have a good color contrast. The most relavent is that your text needs to have proper contrast with the document background.
This is easily done by keeping your text black and your background white, or vice-versa.
There may be times you want to have an aside within your pattern with a different background color, or something to that effect.
There are several ways to check color contrast, but the easiest would be to use a
Color Contrast Checker. This program easily tells you if your text is a sufficient
contrast from your background color.