if you were talking about liquid products, I could see where blending a red product and a white product would give a pink product.  However,   muriate of potash is a dry granular.  And Potassium sulfate would be a white granular - at least I think it is.  So, if you blend a red granular and a white granular, you would end up with a blend of red and white granulars, not a pink.  And you should be able to see the individual red granulars and white granulars.

Am I correct??????