IrishMom -- Welcome out of lurking!!
I think that I probably use too many fabrics and should dial it down a bit or at least make my "color" definitions narrower. In my defense, I'm trying to use up my little bits of things, little strips (when I still cut/saved them), 6.5" strips (my new small scrap size) and 10" blocks and such. With scrappy quilts it can help to use up everything so that you don't end up with the same fabric touching or "too close" to each other. I still use the term "Charm" to mean "only one piece of a fabric" and not as a precut size.
Even though I work in a very scrappy/busy style, with all that chaos I find it very helpful for the finished project to have some consistency so I will be using the solid reds instead of red prints. A single neutral can help too -- or a very narrow definition like all white on whites. But that's just for me -- some people love the riot that comes from charms.
Nice thing is that Bonnie will tell us if we need to make sets of a color unit if the design needs them.
One of the things that makes these mystery projects all the same yet all different is choices on how we make them. I'm typically going for scattered, so would make each step roughly 1/3 each of the 3 colors. You might decide to try and color shift somehow (which I think would be a nightmare in a mystery). You might decide that -- oh! I think this is going to be borders and will make all these units out of the same fabric. And you might be right! Or, Bonnie puts in things to keep use from guessing too far ahead. Some of us (me included) were really annoyed that she had us make excess blocks in the Frolic project (or at least we cut finished blocks in half to use as setting triangles. I got over it and put spare blocks on the back.