Blue!

For those of us with an appreciation for structural colors (bring on the bling!!), there are options other than blue. I just stumbled across a project focused on metallic or iridescent organisms:

Metalloids, at https://www.inaturalist.org/projects/metalloids

Even if joining one more project will make your giant project list un-navigable (I'm getting there), this one is still worth a quick browse. They have some amazing opiliones, shockingly sparkly bugs, and of course, brilliant birds.