http://skyandtelescope.com/observing/ataglance/article_110_1.asp
"Mars shines in the southeast in evening. With your naked eyes, compare it to much fainter Antares, the orange "Rival of Mars," in the southwest. You'll find them at the same height right after dark. How do their colors compare? When Mars is distant and no brighter than Antares, their colors appear more alike than they do now, though of course Mars has not physically changed; colors appear to wash out in an object that appears very bright to the eye. "
Interesting. ...thanks.