Too many brands, qualities, dyes and dying methods to give a definitive answer. There are Navys and Royals that will totally discharge and some that don't do too well. Same with Blacks and any other color.I know/heard navy blue or royal blue doesn't. I know some don't. Wanted to know if anyone knows for a definite.
I don't mean to derail or thread bash, but this isn't quite accurate. Discharge has everything to do with dye selection. Each dye when used has a "discharge-ability" rating based on a scale from 1-5. Not all dyes are affected by discharge, this is why we have different results. The application of the dye has little affect because there isn't a lot of wiggle room in the dye process. Garment manufacturers that are smart will use specific discharge-able dyes to create better shirts for discharge.it has absolutely nothing to do with what the color is. It has to do with the shirt and the way the dye was applied. For best bets stick with something 100% cotton it is rare that they don't discharge, there are a couple gildan styles that don't.
American Apparel's 2001 series all discharge. Including olive, Kelly, navy.