Rainbo-noids? Spectralisms? I dunno. Is there an official name for these?
My question though is, what organisms in your area display a full (or nearly full) spectrum of humanly observable colours?
Here’s my pick for my part of Canada (southern Ontario).
What about where you live?
Possibly on this list?
https://www.color-meanings.com/colorful-animals/
Condylostylus longicornis are usually green but are sometimes seen in a rainbow coloration. It’s a bit like seeing a unicorn, feels very special to spot one. (I’ve seen several now.)
edit to add: nice list in that link, though I was surprised how far I had to scroll to reach a Toh!
These flies are a bit of an addiction for me too. And can easily become a distraction when there’s a bunch of them and I’m looking for newer bugs! ‘Oooh, shiny!’ all the way, right?
Wood Duck is the most multicolored bird I’ve photo’d and they are common in my area so I often just have to get yet another pic of one.
This shot with the related Mandarin Duck captures a lot of color.
https://www.inaturalist.org/observations/195585350
Wow! Quite the chromatic contest there! Great shot.
Pride-of-India, aka golden-rain tree, Koelreuteria paniculata, has beautiful autumn colours and strange bladder-like fruits. In the UK it’s very rarely self-sown from planted trees, but often where there’s one, there’s several. Here’s a clump of some self-sown saplings at a park’s edge, showing red, orange, yellow, true green, purple, and a bluey-green:
It is right there in the name: Rainbow Lorikeet!
That’s the link to the taxon page, because all my observations only show small sections of the birds. It is hard to get a clear shot showing all the colours.
One of the most colorful creatures I can think of is the male Wood Duck. But, even the female has some great color going.
Chrysochus auratus (Dogbane Leaf Beetle)
Ampelopsis glandulosa var. brevipedunculata (Amur Peppervine)
Just an amazing looking lizard!
Love that peppervine! (I’m also now craving chocolate candy eggs)
Or Jordan almonds…
That’s what it made me think of as well! I haven’t eaten those in a while.
Sadly, Arctostaphylos rainbowensis is not actually rainbow colored.
In fact, most small winged insects display WIPs, or wing interference patterns, which may encapsulate the entire spectrum of visible light, depending on the species (as these patterns are species-specific!): https://jhr.pensoft.net/article/111382/
