I would suggest printing out a color chart on a t-shirt and matching your colors on the screen that way. Its alot easier then to get your colors to match with a chart. That way you can see exactly what the color you are putting on your shirts will look like.
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Always do right; this will gratify some people and astonish the rest. ~~~Mark Twain BobbieLee www.brightlittlebeginnings.com
Colour management is a complicated affair.
Firstly you need to be sure that your printer is printing correctly.
Then you need to have a working profile that covers a large gamut or range.
Then you need the correct output profile, this is specific to ink, resolution, substrate and process. So if you change one thing it might not work.
Your question is not very clear, it could be any of the above.
Color, what I see isnt what I get 
