Scratch Pad

  The scratch pad lets you store intermediate colors for later
  use in color mixing.

  To access the scratch pad, click on the scratch pad button in
  any of the color models.

  To store the currently selected color in the scratch pad, click
  on the paint bucket above the scratch pad color tile.  The
  scratch pad adds that color to its list of stored colors.  You can
  scroll through the list with the scroll bar.

  Use the clear button to cancel this list and return the scratch
  pad to its initial state.

  Note that the currently selected color can be one of many
  color tiles on the picker model.  When using other color
  models, however, you can select only the new and original
  color tiles.

  To set the new color tile to a scratch pad color, scroll to the
  new color and click on the scratch pad color tile.  The new
  color tile changes, and the scratch pad tile is highlighted.

  In the Picker color model, this highlighting indicates that
  the scratch pad color can now be dumped into one of the
  interpolator end tiles by using the paint bucket buttons.

  Additional topics:

  *   Overview of the Color Mixer