The rule of thumb is that wherever you use color to give specific meaning, you need a redundant coding scheme, for example, color and line thickness so that people who are color-blind will be able to decipher the code without needing to see specific colors.
Another approach is to pick a color scheme that works for people who have the various types of color blindness.

There are several sites you can use to check how your images or Web site will appear to someone who has color blindness.

www.vischeck.com
www.colorfilter.wickline.org