red in common vft traps

What do you do to make you vft's traps get dark! red not pink i love the way you see them in pictures but mine are only pink how can mine be red inside the traps

Lots of light.

REALLY BRIGHT LIGHT, also the VFTs vary a lot on how dark red they will get, I grow mine about 5" from 4, 40 watt flourecent bulbs and have no problem getting nice bright colors, if this or direct sun does not do the trick for you try getting one of the high red varieties like Green Dragon or all red like Red Dragon.