Using my color table in f(z) selection menu

Use Color Table Waves instead of Color Tables. (It's a different radio button)

I had already tried that but all the "colours" were black when I used it, so questioned how to do it.

I had used dBZ14 and changed the colour order. Saved it and then used as Color Table wave.

Actually JIm I have found that I can directly edit the new color table wave as a table from the data browser working directly on my plots - this will serve my purpose.

You may have already solved your problem, but in your attached images, I noticed you have 'After Last Color' set to black and the max value set to 15. The black colors you had been seeing might mean that most of the streamIDplotkey data is beyond 15. 

Mike German wrote:

I had already tried that but all the "colours" were black when I used it

The color wave editor makes it way too easy to create a color wave that doesn't use the peculiar Igor standard of 0-65535 for color intensity. You probably created either an 8-bit color wave or a 0-1 color wave. You can convert it right in the editor.

Thanks, Jim, Ben and John for advice - I'm still working on it.