Any way to change this icon?

Is their any way to alter this lock icon. I've tried going into tools/customization change the icon a different color or change it from small to medium but it always reverts back to the default. It's too small. Their isn't enough distinction between locked and unlocked. A toggle macro might be helpful too. I have a toggle macro to turn the grid on and off but can't see a way to alter the code to toggle the scale lock on and off.