Automatically set groups based on values of a column. Comparison is done case-sensitive. If more values than specified max. groups exist, create only groups for the values with most Samples.

• Clear existing groups: If not selected, existing groups are not cleared and their colors are kept. If the value in a column matches an existing group name this group is assigned to the corresponding Sample.
• Use color gradient: Instead of using colors that are spread in color space, use a gradient between the two given colors.