r g b use different bits
Due to there being less bits per a color gun (red, green and blue) there are less colors that can be made in 16bit.
%1111 1111 1111 1111 (a 16 bit number) rrrr r--- ---- ---- red part ---- -ggg ggg- ---- green part ---- ---- ---b bbbb blue part
Due to there being less bits per a color gun (red, green and blue) there are less colors that can be made in 16bit.