My bettas are sick, please help!?

[Avery]

my first one is losing all his color(he is very vibrant blue and purple) and now hes almost grey and red. he wont eat much and hes not as agressive as usual. my second fish, an almost totally white male just keeps to the bottom of his bowl. he wont eat. my second i just bought, but my first ive had for several months now. ill change his water, which i havent done in awhile, and ive been keeping him by a bright lamp which probobly changed thier temprature, i moved them, but they still are sickly, i also kept them by eachother, to see if they would flare up, my first one did, but the second did not. i fed them both bloodworms every day,and i try to make sure they eat it. my little fishies are sick, please keep Prince and Ray in your prayers! <3