I think you can, I changed my headlights from white to yellow top coat. They are H4 bulbs. At night, white light is not very visible maybe Xenon???.
Anyway the wattage is the same. The only problem is your PIAA lens cover. If the cover is yellow then you can't do much.

"The 550 utilizes a yellow top-coated H4 bulb when combined with a clear wedge bulb (located within the lamp) and a Plasma Ion lens creates a soft amber glow" - Piaa Website

Cheers