Red and yellow won't do anything for growth. Corals use a lot of blue and a little red for the zooxanthellae to do photosynthesis and feed your coral. They get more than enough red from the 'white' leds which make
'white' by mixing red, green and blue (just like your TV does). It looks white to your eyes, but the coral doesn't have our eyes and they still 'see' red green and blue. The red and yellow leds may add enough red that may help with growing some nuisance algae though. The purple (violet) is good for coral.
If you want better growth, pull some of the white leds and add in different shades of blue than what the fixture already has. (example: you 440nm blue now, so add 420nm violet, 450nm, 460nm and/or 480nm blues). That will help the zooxanthellae grow more food to feed the coral polyps for better health and growth.
