Color: The Newest Tool for Technical Communicators
http://www.ingentaconnect.com/content/stc/tc/2003/00000050/00000004/art00010
  access restricted (by the publisher) to members/subscribers/customers only
  peer-reviewed

White, Jan V.
Technical Communication Online
2003

Abstract:

Asserts that color must be used to make information clear, lucid, powerful—faster; its logical application must be controlled by the editor. Provides a comprehensive checklist to help editors use color effectively.