I have had both red eared sliders and painted turtles in my outdoor ponds and fish tanks in the house. They are as much fun as the fish. I don't think they are any dirtier than goldfish. My water is always clear. The turtles haven't hurt my fish, but they do like eating crawdads, slugs and the fish food. They swim over and beg for food twice a day. I have pictures on my web site. Here is a link that might be useful: My pond page

I'd say the color changes take place after the molt. Think about gulf frits, and how their spines are clear right after they molt, then the black color gradually appears. I'm no scientist, but in my observations, the color change comes during or after the actual molt, certainly not before. MissSherry P.S. It's funny you should post about molting. I noticed a cicada - the regular summer type - on a piece of cudweed today, with the old skeleton just below it. The cicada was clear colored and didn't appear able to fly. When I came back to the same cudweed a few hours later, the wings had darkened and didn't look so fragile. I'm clueless about cicada life cycles, but it looked like this critter changed color after molting, too.

Thanks, agarden, for reminding me of the reason I don't feel compelled to correct others of their accidental misspellings or grammatical errors. You are making a good point, however, and it's worthy reminding everyone that it is important to ID a questionable animal (using animal in the broad sense of the word) before taking action to eliminate it. There's not a day that goes by without someone being gently (usually) scolded for taking action first, asking questions later. However, common sense should come into play, as well. Accidentally deposited insect eggs are observed fairly frequently, judging by the number of questions we have fielded regarding eggs or recent hatches on window screens, fence posts, and other inappropriate or surprising locations. As has been said earlier, moths are the likely culprit on porch ceilings and windows, since so many are strongly attracted to the lights. The caterpillars that hatch are doomed unless there just happens to be an appropriate, easily accessible host plant growing very nearby. Few people are equipped to raise lepidopterans, especially if unidentified. As a matter of fact, few would know how to even handle these hatchlings in order to transport them elsewhere. (And then....to where?) This is where the common sense comes in. These will end up as lunch for a lucky predator, and there's nothing wrong with that. But if it were MY porch, I'd clean them off.

Ned stated it well, but to go a bit further, there is no blue pigment in any of the birds you see that appear blue. Like Ned said, the color appears by refraction. The structure of the feathers reflect back the blue light. Here is a link to a page by Cornell that explains feather colors. It's pretty fascinating. Here is a link that might be useful: Cornell Lab of Ornithology - color