Some of these colors are not great splitters-- they're primaries, so they naturally don't have anything to split into. We keep them in our palette, though, because we use our dyes for bottle dyeing, Shibori, and low water immersion, too. They're also great for adding alongside the more complicated colors! In general, you don't need any primary colors in your ice dye repertoire unless you're using them for other dye applications.