It might be the lighting, Or the fish in the shop could be stressed and arent showing there full colors, but in your tank they are doing better and not stressed so the fish that you have might have more vibrant colors
Lighting is a big problem. Most LFS use dimly lit tanks to keep them in so alot of beautiful fish often get over looked for others. But yours sounds like it's the other way around.
What kind of lighting do you have in your tank? Do you notice a different hue between yours and the LFS? Also, what colour substrate do you and the LFS have? This can make alot of difference as lighting can reflect in a different way and it can also make your fish feel more/less secure.
What fish have you got? the tank looks quite bare so you might want to add more plants and things or maybe more fish depending on what you have. If you only have say 5 neons in that tank i would expect them to be washed out
There all shoaling fish pretty much to a degree. they need more of there own kind especially the neons. you might find that your frog enjoys them for dinner though