The [cpt-city](http://soliton.vm.bytemark.co.uk/pub/cpt-city/) website has a large collection of over 4,000 color tables ([download](http://soliton.vm.bytemark.co.uk/pub/cpt-city/pkg/) of over 4,000 color tables). Unfortunately for us (i.e., me), they are all in the `.cpt` format used in GMT. Here’s a [routine](http://michaelgalloy.com/wp-content/uploads/2009/12/vis_cpt2ct.pro) to read a `.cpt` file and return it as a 256 by 3 color table array:
IDL> rgb = vis_cpt2ct(‘gmt/GMT_copper.cpt’)
IDL> help, rgb
RGB BYTE = Array[256, 3]
IDL> tvlct, rgb
Now I need a catalog that I can scan through to find a color table.