If they're over-rated (higher wattage than stock) then they're illegal.
If you remove the yellow part of the lens, then you need to put a yellow bulb in place of the white one. Laws are very specific when it comes to exterior lighting color, so don't mess with the color. Green turn signals, for example, are not OK. Clear tail lights that don't have a sufficient amount of red reflector visible are also unacceptable. Those red bulbs some people try to get away with in the tail lights always look pink-orange and are therefore ticket magnets.