It would be useful to have the option to choose colors not only based on the strength of the correlation but also on its sign (negative/positive). This way it would be possible to know the type of correlation without moving the cursor on the specific box. For instance, a strong negative correlation could be assigned an intense color and a strong positive correlation could be assigned a different intense color, both gradually fading to a neutral color (like gray) where there is no correlation..
Thanks
Carlo