Consider the pumpkinseed. In a world full of voracious predators this sunfish species goes through life with ridiculous clown paint Non Camo! Common here in the US they are actually a rather pesky invasive species in Europe.
Strange Fish caches are more whimsical than challenging, so this is a simple Park n' Grab. In fact you can pull in right next to it. There are often fishermen and walkers about, so be a little sneaky. When placing this cache I just brought my pole with and nobody suspected a thing!