really imporant/urgent day gecko question

[bob_thesnowman]

hey guys
i have a day gecko that i've had for about six months,recently parts of him have started turning,a blueish purple color,he's acting like himself,still skittish as hell,plump,and will eat when offered food,but the color is all located in one area between the vent and it goes up for about 1/2 an inch,something tells me though that there is something very wrong....do day geckos turn different colors when they become impacted,i tried to search for it on the internet,but i only found it on one site,and it was very very vague,he's currently on a mat,so substrate impaction is not an option,but he's had a few more butterworms then usual lately,and i've had a bad experience with a butterworm giving a young beardie a seizure,after some injections of various fluids she recovered,and is growing like a weed today!but what do you guys think,i do worry alot about my little guys,but something just tells me there's something really wrong here!!!please help!

Chris