SB-15 (small batch) is a blue creme with subtle orange shimmer.
SB polishes are small batch mixes with limited quantities. Once SB-15 sells out, it will not return to the shop.
Opaque in 1-2 coats, depending on application.
I use high-quality & highly saturated pigments in my products, so staining is possible. It’s always advisable to apply a worthy base coat, especially under darker colored polishes.