One of the big problems in using a library is that you are denied the opportunity to learn. You have to learn what all the functions and methods do but that learning is not transferable knowledge. To fade down you need to reduce the red, green and blue values in the display buffer. But you seem to use a method maximizeBrightness , so read the documentation to see if their is a minimizeBrightness method or try a negitave value in the method you use.
On the other hand you could code it properly.