How can I change the reference column for symbol colors?

I have a file of focal mechanisms like this:
70.22 35.92 192.8 61 71 79 TF

Fields are in order: longitude, latitude, depth, strike, dip, rake.
I’m using gmt coupe function of GMT 6.0.
Normally the color is decided by the depth in the third column but I want to change and I want that the CPT file that I have must be referred to the 7th column. Is it possible?

A few comments:

  1. Your 7th column seems to have text so that wont work with CPT lookup
  2. To shuffle input columns you use -i and select the order you want so that the column you want for CPT lookup is the 3rd (e.g., -i0,1,6,2,…)
    3.Never a good idea to use so old GMT versions since we do not look at problems unless reproducible in the latest version (6.4).