**** blicks has better dye and they sell nylon dye which spandex has alot of the colors are richer than rid and whatever joann sells. they also sell textile ink for making t-shirts so you can make your own for figures as well just look at youtube tutorials
Just an fyi when dying mixed fabrics like t-shirt knit that is not cotton just pay attention to the percentage and use dye that works with the fabric type it contains.
For example 70% polyester 20%rayon 10% lycra look for something that will work with poly and just a note poly needs hot water to activate it to take dye and salt must be used with colorants it acts to soften the fabric to open pours to take the dye then wait time and when dyed to color you want which will look darker wet use cold water on final wash this closes pours locking in the color.
and alow to naturally dry so use liquid softner in the final hand wash in cold water before you let air dry