Using a sublimation printer is new to me. One of the concerns I had was learning how different colors on the computer would translate into colors on my colored t-shirt. Instead of trying colors one at a time or as needed, I decided to just print a 1-inch color wheel on the bottom and side of a test shirt. If the test shirt turned out well, the color wheel would be no more obnoxious than the print registration markings that appear on all sorts of products we use all the time. While I was at it I decided to see how much deterioration of appearance would occur if I used the print-out a second time. The image on the right shows a much dimmer image, as would be expected.
The color experiment worked very nicely and effectively informed my design decisions. You really cannot get yellow on a blue shirt. Broad patches of yellow ink look green (as you might suspect). Orange print results in a brown image. The main thing you have to watch out for is that your brain tries to adjust, so at first glance the place on the wheel where yellow should occur looks yellow, but if you isolate that spot and look at what is really there, you will see that it is green. You can then adjust the colors that are printed to get the colors you really want on the t-shirt (provided you are not fighting physics by trying for yellow on a blue shirt).
The color wheel is a cropped screen shot right out of Microsoft’s Paint program.