It's really fun trying to complete a color challenge for a specific pet model. At the end, I feel really accomplished, and my collection gets one step closer to being "complete". But let's be honest, a collector will never run out of things to hoard! :P
Why haven't I included some of the most basic pets like rats/mice? Honestly, those are so common and the colors aren't exactly all that inspiring. :x I completed that color challenge without even trying so it wasn't worth noting imo.
Anyway, every color (that's available to players) plus all wild pets are rare quality. Many screenshots after the jump!
Top: Savory Beetle
Left column, top to bottom: Beetle, Twilight Beetle, Fire/Lava Beetle
Right column, top to bottom: Crystal Beetle, Dung Beetle, Gold Beetle
Top: Eternal Strider, Mirror Strider
Bottom: Aqua Strider, Dancing Water Skimmer
Top: Ancona Chicken
Bottom: Szechuan Chicken, Chicken
Top: Rapana Whelk, Rusty Snail
Bottom: Silkbead Snail, Shimmershell Snail
Top: Both Sumprush Rodent
Bottom: Both Bucktooth Flapper
Top: Mei Li Sparkler, Darkmoon Glowfly
Bottom: Shrine Fly, Effervescent Glowfly