a bag contains 4 red, 3 blue,5 white markers. three markers are drawn. whats the probability all three are different colour.?

so there must be one red,one blue,one white drawn.

say a red is drawn first so 4/12 than the probability of the next one being drawn not being red is 8/11 but i can not work out the third one becuase for the second disc drawn i do not know if it is blue or white so i am confused