I don't know if this is new in CC or if there is a setting somewhere ( I am coming from cs3 to cc). How would one get the colored (red) brush sizing when alt-right clicking to change the brush size? Mine just shows the black ellipse outline, not the gradient edges for the brush. I am on a Mac with an Intuos pro.
The shortcut Alt + right click + drag left or right is the windows shortcut.
On a mac it would be Ctrl + Option + Left click + drag left or right
A couple things to note:
1. Use graphics processor needs to be checked under Photoshop>Preferences>Performance>Use Graphics Processor
2. The colored preview with either windows or mac, using the above shortcuts, only works with the default round brushes (brushes that the hardness can be adjusted) or presets made using the default round brushes as a base
Sampled Brushes won't show the colored preview.
I did load all my custom brushes in, so you are right. For some reason I remembered it working on custom brushes in cs3, but I could be mistaken. Thanks though.
Just as a side note for anyone searching this issue in the future, it is 'ctrl-option click and drag' or 'option-right click and drag' on the mac.