Working lines have bi-colors but I wouldn't call them red. I've never seen a bi-color that has the same red like a really red WGSL.
Getting what you want from a WGSL is not impossible but you have to look very carefully at the pedigrees and dogs being bred and know what you want. Be very wary of just titles themselves, you'll want to actually SEE the parents working. As recent threads and video footage of the BSZS prove, most of these dogs have SchH3 titles but can barely heel 20 paces and won't engage in bitework. I have a very red WGSL male that is titled in many things and holds his own against many working dogs but it was very important for me to get a good understanding of his parentage. In some respects I also just got lucky because when I bought him, I didn't intend to do Schutzhund. I knew his mother well and saw her train and work many times. I never met his father because he was in Germany (now Denmark) but spoke with his breeder/owner and others who had seen him work before he was sold around just to be bred and never trained or worked after that. If I were to buy another WGSL (which I'm sure I will), I would take my time to find the right breeding.
Liesje & the K9s
Nikon (GSD) U-CH SG SchH1 KKL T1 FO PA TFE-I FDCh-S CL1-R UJJ U-CA HIT TT CGC, free reign semi-retiree
Coke (All-American), couch warmer extraordinaire
Indy (All-American), flyball star in training
Rainbow Bridge Kenya (GSD) U-CH FO OB1 CL1-R CL1-F RA HIT TDI TT CGC