I’ve recently enjoyed both the topics about Blue and Red Organisms, https://forum.inaturalist.org/t/what-are-some-blue-organsims-you-have-photographed/59163 https://forum.inaturalist.org/t/seeing-red-colorfully-attired-organisms/62135 so show me some yellow organisms you’ve seen.
I get a lot of yellow as an hymenoptera specialist, some of my best: American Thief Ants (Solenopsis molesta) attacking a Pavement Ant (Tetramorium immigrans) https://www.inaturalist.org/observations/214843188
I was thinking about what I could post on this thread and then I remembered that my iNat profile photo is a yellow isopod.
Mine is a yellow organism too! It’s a Thief Ant
Brimstone Clubtail, one of my favorite dragonflies that I got to pursue with the late great Greg Lasley. Greg called it “the beautiful blue-eyed blonde.”
Those are such cool dragonflies, I got to find some last year near El Paso
Long tailed salamander
It looks like a gummy candy 
Has an amphipod friend too
Yellow has both my favorite lichen, the wolf lichen! And my favorite species in the world, Cypripedium! Both of these observations caught me by surprise, we drove into the mountains to see larch trees in fall colors, but then all I took pictures of was the lichen growing on them instead 
And the lady slippers, we were trying to find a Corallorhiza spot from a few years before and instead ran straight into the most gorgeous Cypripedium plant, high up in the mountains and still in full bloom when they were long done at my usual spots.
As you can tell, I’m not very good at identifying either fungi or plants :P
While there are plenty of yellow organisms from other taxa, I thought I’d share a few of the yellow lichens I have observed. I think all of them are rather common species, but I find lichens are very pretty when looked at more closely:
These threads are such fun!
For yellow, I have been resisting the urge to post countless Vespoids, and instead chose this member of Ophioninae for its yellow head. These guys are nocturnal, but you can sometimes find them during the day hanging out on the underside of a leaf, they are almost surreal, with an extraterrestrial looking head.
The obvious choice is a flower crab spider when hunting from/residing on a yellow flower. You frequently spot the hoverfly before you spot the spider, as I suspect is also the case for most of their prey!
A list of yellow organisms couldn’t be complete with a Ploceus weaver. The cape weaver has a wonderful orange mask that delicately blends into the yellow body.
The flower crab spider photo is triple yellow!
This locust borer.
And don’t forget the beautiful yellow flowers!
Yay, another color thread - thank you!
Celithemis elisa (Calico Pennant)
Spilomyia sayi (Four-lined Hornet Fly) on Solidago sp.
Allograpta obliqua (Oblique Streaktail)
Arcyria (couldn’t get close enough to get better photos of this beautiful slime mold )-; )
Lachnum pygmaeum a tiny, tiny fungus
Ariolimax californicus (California Banana Slug)
