LIke it says does it stay themed if you just lighten the colors?

It retains the themed name and if bred with others of the same theme will make babies with the purebred name, however the point of a theme is the colour scheme, so most theme breeders will not consider a dyed theme as a 'true' theme. But, Krin introduced the ability to reset any dyed theme's colours back to the true theme colours, so this is less of an issue than it used to be. Once you dye the theme, a button will appear on the pet's profile that will revert the pet to the actual theme colours if you click it.

Ok thank you so much

Because I never normally dye themes, I either forgot or didn't realize that themes could be reset if dyed until recently nor did I know until talking to Krin in region chat that this is a useful way to correct color swing. I don't know how many themes I passed on buying because their swing looked bad. Just need to remember to not do this with any color variants that are no longer the new official version.

Yes! It's a great mechanic for correcting colour swing! Just need one lesser dye to be able to correct to the proper theme colours ^__^