HBrite (Mode Menu)

This mode is only available if you are using 64 colors (Extra halfbrite
mode - Available on ALL A500's, A2x00's A3x00's and SOME A1000's).  In this
mode, painting with the left mouse button darkens colors in a painting to
their halfbrite equivalent, while painting with the right button lightens
halfbrite colors to their normal equivalent.

NOTE: Although Extra-Halfbrite provides you with 64 colors, only the first
     32 are user-adjustable - the last 32 are just half-intensities of the
     first 32. The palette controls can not be used to adjust the halfbrite
     colors directly. You must edit the corresponding color in one of the
     first 32 positions, then the halfbrite counterpart will automatically
     be readjusted. Additionally, you cannot copy to or delete any of the
     halfbrite color positions, but you can copy a halfbrite color to any
     other position in the palette. 

          SEE -> `Arrange`