? about prepping dark BG's

Mrs. K in TX

I bought 3 BG 4.0's at a local store yesterday- colors ribbit (darker green), moonbeam (darker blue), and clementine (orange).  I noticed when I got home that the packaging says to wash the darker colors 6 times separately before washing them with anything else.  Is this really necessary? Will they bleed on each other in the wash if I wash them all together? That seems like a big hassle.  I didn't have a problem with my darker diapers from other brands. I have darker ones from Thirsties, Fuzzi Bunz, and Rumparooz.