MAC Studio Fix Fluid SPF 15 Foundation - C55 (rich brown w/ golden olive undertone for dark skin)  - C55 (rich brown w/golden olive undertone for dark skin) Studio Fix Fluid SPF 15 Foundation - MAC put Studio Fix Fluid SPF 15 Foundation to the ultimate test of seeing how long it wears and, not surprisingly, the formula lasts for a full 24 hours! This modern foundation combines a matte finish and medium-to-full buildable coverage with broad spectrum SPF 15 