Do they even matter? I know fish really only see the bottom of the frog, but I feel like it would just be silhouetted (only looking dark.) against the brighter sky, no matter what color. Any thoughts?

To me it doesn't. I fish a black frog 90% of the time, white the other 10%. Not a lot of frogging water around here though so that may not apply everywhere. 

I throw a black frog most of the time, but I do feel like color matters for frogs to some degree. Unless the fish was looking directly up at the frog, it could still see the sides.

I have 3 colors - black, white and yellow.

I believe colors make a difference when frog fishing. There may be days where any color seems like it will get hit, but there other days where just by changing the color determines the difference between having your frog looked at vs having it crushed.

I think the black frog is the one, but mobody ever really talks about the skirt legs' colors. Sometimes they want 1 color in em, other times 2.

Also, I have some white and orange frogs I'm gonna try out this year. Sometimes I lose sight of black or green frogs in the really thick stuff.

If it's over top of matted vegetation without any holes, I don't think color seems to matter much. However where there are more holes in something like pads or in open water color matters more. If you don't have much for waves on the water, the surface actually can look like a mirror if looked at from an angle. When those conditions are present as the frog rolls on the walk, the color of the top is actually reflected downward. 

I've always went with light colors during brighter days, darker colors during cloudy days and black during twilight. I've done well with this. But it could be just confidence/ placebo effect. There have been times where it didn't matter. I was getting blown up on one day and a my knot gave way. Lost the frog and tied on a different color only to be exploded I again.

I just realized I posted this in the wrong topic area, but thank you for all of your answers!

I've always went with light colors during brighter days, darker colors during cloudy days and black during twilight. I've done well with this. But it could be just confidence/ placebo effect. There have been times where it didn't matter. I was getting blown up on one day and a my knot gave way. Lost the frog and tied on a different color only to be exploded I again.

That's what I'm saying. Maybe it's just wether the fish is in the mood to eat or not. Not so much the color. Hmm...

I've used black and white, and a natural color. 

I use whatever looks good to me. I dont care what the fish thinks

I believe that the top water strike is a reaction strike not a pondered strike on what the Lure looks like having said that the bottom half color catches fish and the top half color catches fisherman like most have said you choose either a dark or light color for the bottom half depending on the conditions pretty much white or black take your choice. I'll say this, when the top water bite is on you could throw a turd out there was a treble hook hanging off it and you will catch fish