blue (color)

back / a backer, a supporter (someone who supports a person or enterprise) / reversing, moving backwards

(sex); go back / move backwards / give a refund

back / reverse / rear / support / background

Abbreviation of ブルーレイ (burūrei, “Blu-ray Disc”).

blue jeans

light blue (color)

(cosmetics) being blue-based; having a blue undertone to one's skin

blue tarp

(organic chemistry) bromothymol blue; BTB