Sometimes they grow the big leaf crotons in shade. They can tolerate, and even prefer some sun so you should be okay. give it some plant food and new leaves will soon replace all the lod ones.

OMG no don't fertilze them now when they're stressed and newly transplanted. Sheesh!

Is your soil very sandy? You may have to water them twice a day until the rainy season starts (that is if you're in FLorida).

Yellow crotons can take more sun. Any other colors like filtered sun, especially in the afternoon. Crotons respond well to rich acidic soil.
A sprinkling of coffee grounds will help them produce a new flush of flowers. I would not fertilize them until they are established. I suspect too much sun is your culprit.
I would water in the mornings too. Night time watering encourages problems. Keep us posted

Thanks so much for all the advise.. Water..that seems to do it. I have a window a/c and the one under it, where it drips is beautiful. I wasn't giving them enough water. They are looking much better now. They will have to deal with the sun, but I can give them all the water they want. I dont think I am going to loose any. Yay

Maybe some of the crotons just weren't used to full sun? I guess the true test will be to see if the new leaves coming look better. I grew a big leaf croton in the flower bed last summer in full sun and it did quite well. Then again, maybe full sun here isn't as intense as down south.

When crotons droop it is usually a lack of water. They are very drought tolerant when established. They do not need any fertilizing, I have been growing them for many years and have never fertilized them. They adapt well to all soil types..I have an alkaline soil and they are very happy.

Here is a link that might be useful: my rustic bajan garden

On a lark I planted some that were purchased at a grocery store, the big leafed variety, with the intention of digging them up come late fall. I live in a very humid area in south Georgia on the banks of a lake, my humidity is never below the high 80s this time of year, normally in the 90s to 100% lately cause we have had some rain every day except a couple, for the past month. Mine started putting on new leaves within a week of being in the ground and every stem is putting on numerous leaves. It is in full sun. It must be the humidity, every morning at sun rise it is dripping water, they just love it.