coloured bulbs or LEDs are good for viewing the snake in the viv but as long as they get a day/night cycle through a window they're fine
if you're wanting to try and manipulate the snake's conception of the time of year you can increase or decrease the number of daylight hours accordingly eg. if you're a breeder wanting to start the season early you can give your snakes a longer 'day' using artificial lighting (although daylight hours is only one of triggers to let a snake know it's Spring)
cornsnakes, ratsnakes, bullsnakes, boas and day geckos