Sublimation prints looking terrible!!

I have a small sublimation printer (converted) and when I buy a file off of etsy or somewhere else, the mugs look great after I press them. When I design something in illustrator and print it, it looks HORRIBLE! The blacks look fadedwith a goldish tint, the brown dulls out to almost a pinkish color, etc. I print the etsy files out of illustrator as well. What would cause my designs to NEVER look good? I have included a picture so you can see what I am talking about (IGNORE all the other designs - these are booboo tumblers that I use for test prints to make sure they are going to look good before I waste more lol). The 777 and the bison should be brown and the triangle should be black. On the other tumbler, the native design is one that I did not do and it prints perfect. Could it be the color setting in illustrator? But wouldn't it do that for both designs then and not just mine? HELP!!