start up the heat is higher than halogens b/c the hid bulbs need to warm up... reason why you see a color shift when you turn them on... but once the light is at to the temp it's unning on less volts and less heat than oem... so there is a chance of melting...

is this aftermarket projectors or oem?
reason why i ask is that if it's aftermarket projectors if i were you swap the projector housing with an oem HID projector like the s2000/audi tt, etc... and use a d2s bulb with a d2s bulb wire harness to your aftermarket ballast... that way you get an OEM projector look, but also the brightness on the road... if you do that don't go over the 4300k oem bulbs... or you will lose the lumans aka brightness...

it would be ideal if you let us know what you are using... and for what car...