Gradient with 2, 3, 4, 5 colors using API

Draw gdadient with 2, 3, 4, 5 colors using API I have see similar code here (using API) for some gradient effects, but I haven't found a project that give the users the option to select the colors to draw the gradient. 2 colors -> the classic (horizontal or vertical) 3 colors -> same as above, but with a 3rd color in the middle 4 colors -> each color in a corner 5 colors -> 4 colors in the corners and 1 in the middle (the screen shot isn't good)