Ability to color histogram by X or Y axis

Please add the ability to color the histogram by either X or Y axis. Allow this to be either categorical colors or by color map. Example would be:

• disk_out_ref.exo. Load all variables. Apply.
• Histogram filter. Color by Temp. Apply.
• Now, I want to change the color going left to right.
• Alternatively, I want to color by magnitude of each of the bins.