[NTG-context] Changing the colors of Charts in luametafun

Hi, as I'll need to make some business charts in the near future I had a look into metafun xl. Here is the first example: \startMPcode draw lmt_chart_circle [ samples = { { 1, 4, 3, 2, 5, 7, 6 } }, percentage = true, trace = true, ] ; \stopMPcode How can I change the colors used for the sample? juh