Wrapping a color macro around a noformat macro has no visual effect in any browser I've tested in Confluence.
However, in IE7, but not FF2, if you wrap a color macro around a noformat macro, then the whitespace in the noformat block will be lost when you go to the rich text editor.

Example markup (edit issue to see it, because noformats don't wrap noformat) (note that in jira the color actually has effect)

     indented text
text on new line

From IE, roundtrips to

indented text text on new line