Options for configuring the palette grid can be found on the Appearance tab in the Options dialogue. The grid can either be of a fixed size, or variable based on column count.
Configure the grid to fit to columns
To have the size of the swatches in the colour grid size themselves to fit a given number of columns
- In the Palette Grid group, set the Mode to Variable
- Enter the number of columns you want the grid to support
Setting the grid to a fixed swatch size
To manually set the size of the swatches in the colour grid:
- In the Palette Grid group, set the Mode to Fixed
- Enter values into the Swatch Width and Swatch Height fields