RGB Math: If Component Weirdness

I'm having trouble getting the IF component to produce expected results when colors are involved. Specifically, colors other than the THEN and other than the ELSE are showing up in the result.

The attached example shows some color bands fed into SOURCE A and the color purple (1, 0, 1, 1) fed into SOURCE B. It successfully turns the purple area into the grey specified by THEN, however, the non-purples are turned into a strange mix of SOURCE A, THEN and ELSE rather than just the ELSE color.

If you alter the gradient to use only grey colors and change SOURCE B to a matching grey, the IF works as expected -- for the most part. However, even in this case, the alpha on the ELSE will be ignored, and the alpha on the THEN will affect the alpha of the whole output, not just the matching color.

Ah, thanks for the clarification. Although I can see some uses for the IF component as it is implemented, I think one that worked the way we both expected would be more useful. It would be nice if there was a checkbox to allow us to use either behavior. This seems like an easy Map Script to whip up.