I have a mouse mouse from speedlink that is able to do a lot of things, like changing the colours of the leds, but I can only do those things with the provided software from speedlink.
Is it possible to code your own software that controls the led lights of the mouse?
Yes, but you would have to have the hardware specifications to know what needs to be sent to the mouse to accept the commands you're looking for. Usually these things are not published or readily accessible.
I bought two Microsoft Basic Optical mice, identical to the one which performed the functions I needed really well. The first one would grab and flip the grid with object in one position within the grid with a right click of the Mouse. The Blender 2.79 3D modelling app is what I am using the mice for, I plugged the two new mice into two computers, to try them out, they would NOT do the grid grabbing and flipping, though they would perform the other functions. the grid grabbing function is important so that You can move the scene and inspect the model, or appear to walk around a solid object in the real world.
