Yellow in the print is common with the Epson's c88's and I guess the C120's. You have to go into printer settings, and go to color control. Most settings go something like this: magenta +5, cyan +5, yellow - 10 to -20 depending on how much the yellow is pervading the image. The magenta and cyan are optional. I do those settings, and they are common settings among other Epson owners.
I have heard that folks who convert over to 3rd party inks do not need to adjust for color anymore. I haven't gone there yet, but that sounds nice. Good luck to you, hope this helps.
Wait a minute, re-reading post. My answer applies when the image is printing with too much yellow color, which transfers to the shirt with too much yellow.
Now I think you are saying something else. Are you saying the picture looks fine printed, and after you finish pressing it, it looks yellow? You may have a scorching issue at hand.
Some Q's I have:
Is the yellow only where the design is, or does the yellow go past the design and appear on the shirt as well?
You said your temp is 360*, but how long do you press for?
What press do you use? Have you tried to verify the temp it is running at?
What shirt do you press onto? 100 cotton or a cotton blend?
Do you use a teflon sheet?
What paper do you use?
What ink are you using?
What are you printer settings for the yellow in color control?
I know they are alot of Q's, but it'll help to figure it out.
prints turning yellow 
