Makecpt gives output with one colorname and rest RGB values

Q&A
1

The following command produces a CPT-file with RGB values, except for the one color, mediumaquamarine. Why!?

$ gmt makecpt -Cearth
-11000	black	-9625	31/40/79	L
-9625	31/40/79	-8250	38/60/106	L
-8250	38/60/106	-5500	53/99/160	L
-5500	53/99/160	-4812.5	72/151/211	L
-4812.5	72/151/211	-3437.5	mediumaquamarine	L         <---
-3437.5	mediumaquamarine	-1375	141/210/239	L         <---
-1375	141/210/239	0	245/255/255	L
0	174/239/213	60	175/240/211	L
60	175/240/211	120	176/242/208	L
...

This breaks a script I’m using, hence the question.

2

see makecpt -F option docs
default is write color names if possible, can be configured to r/g/b codes only.

-F[R|c|g|h|r|x][+c[label]][+kkeys]

    Force output CPT to be written in the desired format set by the directives, thus selecting among color names, single gray-scale values, color names, r/g/b only, h-s-v, c/m/y/k, or #rrggbb hex codes. Choose from:
        R - Output color names if possible (and use r/g/b otherwise) [Default].
        c - Output color using c/m/y/k values.
        g - Output gray singles (will transform any colors to gray via YIQ transformation).
        h - Output h-s-v triplets.
        r - Output r/g/b codes only (even if a color name applies).
        x - Output #rrggbb hex codes.

...
4

Thanks @mkononets.

I thought that RGB output was the default since there was only one line with a colorname in the output.