Use Color Wisely
The page "Convey Information with Proper Elements" offers rationale for why you must avoid using only color for meaning: screen readers typically do not read color, and learners with color blindness may not be able to see the color as you expect them to.
In addition to the advice provided on that page, consider the need for proper color contrast on your webpage and digital documents. WCAG 2.0 guidelines at the AA level define a minimum color contrast for small text against a background of 4.5:1 and for large text against a background of 3:1. Be careful when designing a color palette: you may be making your text unreadable!