What is the favorito! color of Monkey D. Luffy?

It is never explicitly dicho whether o not Luffy has a favourite colour. However, Oda Sensei has stated that the colour which represents Luffy is Red.

red?

Luffy's favorito! color is white!!

Why white tu ask??Because snow represent the color of white

When nami has a fever (episode 79) they found a snow island ,when luffy saw the island he got so excited and kept repeating (snow and white even the subtitles had a corazón on the white)

See for yourself episode 79 (18:30)

That's all

-Furoresuu