Your images are out of the gamut of what printer ink can do. In other words, your image would not look like that on a tee shirt.
This is the image corrected for gamut. Also not sure you'll get a t-shirt dyed with that background color. I would ask for some guidelines first, otherwise, you are "painting in the wind". What color are the T-shirts, and what is the size and placement of the image? Are they going to be silkscreened or ironed on?