Colorbar giving error in GMTmex

@richannan Please do not post screen captures, Just copy your code and put it under a pair of triple backticks ```

Using colorbar works for me but I have GMTdev and maybe we fixed some problem related to it (there have been tons of fixes after 6.0).

You can try a very recent GMT build from
http://www.joa-quim.pt/mirone/downloads/gmt.html