Pale ADF compared to others

[Murray of the Deep]

I have 3 ADF's 2 of them are bigger and more colored than one of them. He is paler and tiny. When I feed them bloodworms with tweezers the 2 big come out and hog the food while the tiny one is slow and does not eat very much. Could he be sick, stressed, shedding? IDKK help! i told my hubby i wanted to look at him close and he decided to put it in a glass lol pale/tiny is on left and one of the big is on the right

your frog is malnourished try seperating him to a tank and feed him there