Primary Color Grading

Primary color grading is the first creative phase of grading, in which the colorist establishes the overall tonal character of each shot by adjusting parameters applied to the entire frame at once. The primary controls are organized into three or four tonal zones: lift (or shadows), gamma (or midtones), gain (or highlights), and on some platforms offset (a constant added uniformly to all values). Each of these zones can be independently adjusted for color (R, G, B balance or color wheel rotation) and luminance. The ASC CDL standard encodes the primary correction in just nine parameters per shot — Slope, Offset and Power per channel — making it the most portable form of color metadata. A typical primary grade pass involves: setting the white point (gain/highlights) so that bright neutrals look correctly white; setting the black point (lift/shadows) so deep shadows have appropriate weight without being crushed; setting the midtone gamma to control overall mid-frame brightness; and adjusting per-channel color balance to neutralize unwanted casts or warm the shot toward an intended emotional temperature. Primaries are non-destructive and are stored as a node tree in modern grading apps. The primary pass is foundational — secondaries (isolated region adjustments) and stylistic effects (film emulation, grain) build on top of it. Reference: the ASC CDL specification and grading textbooks by Walter Murch, Patrick Inhofer, Alexis Van Hurkman.