if you touch the bulb you need to clean it asap to get your grease off of it...it will make hot spots on the bulb and ruin it pretty quick just from your natural skin oil....never idea to touch a bulb...especially not an HID. Major brightness change when you 1st turn them on is normal as the bulb warms up (like a florescent in the way it warms up and gets brighter) but not sure on color...my 4300-5300 (white) never changed colors during turn on.