I love dying things maggie,
last time was end of last year, three old sweater shop t-shirts, a faded navy one, a white one and a yellow one.
I dyed them all with dylon navy, the navy one looks just like new, the white one came out a paler blue and the yellow one ended up a sort of jade colour.
the embroidery on all the t-shirts stayed exactly the same, didn't take on the dye, and I now have three tops, like new. X
You do have to be careful with the stitching on things when you dye, because it very often is not cotton thread and doesn't take on the dye.
I dyed a pair of jeans black last year and they came out black with white stitching!