"Shimmery" sounds like some of the shiny reds to me.
Re color clarification and muddiness... Some yellows carry a "mud" gene, which can be hidden by the yellow color. My understanding (perhaps incorrect) was that it had to do with lycopene, which I thought was present in melons.
My understanding is that to clarify color, you want to use a clear pink or a near-white, and I vaguely recall someone saying that they had better results with the clear pinks.
