oh just to let u guys now i havent tried this yet but going to once i get my boards
edit: IF YOU WANT to avoid the stress of cutting a hole in a straw (dont wanna give ne1 gray hairs) put the led INSIDE the straw and seal the wire coming out with some tape. id guess this would eliminate the chance of any white light coming out but once again dont wanna stress you guys it with cutting a hole in a straw
TIP:: if you want take a knife and make an incersion in the straw and force the led up in that incersion... just make sure you dont see any white light coming out of the incersion becuz that will ruin the effect (well unless you have a white car)
TIP 2:: use washable markers they colour on clear and are usualy vibrant
TIP 3 :: if you want a POWERFUL underglow change the leds to whatever colour you want but if you want a soft one do it my way
TIP 4 :: if you want a vibrant colour direct the light downwards by using aluminum foil and shape the foil so that the light doesnt go up and hide inside your xmod but is bounced back to the ground (the aluminum foil should also make it a bit more vibrant cuz of the shine)