Colour theory for photo editing: the basics

Applying presets is a start. Understanding them is the next step. Those who know how colours interact can adjust and refine any preset instead of depending on what the creator intended.

The colour wheel is your starting point. Complementary colours (opposite each other on the wheel) enhance each other: blue and orange, red and green, yellow and purple. Many film colour treatments use blue in shadows and orange in midtones. That is no coincidence but colour theory in practice.

In Lightroom you use the HSL module (Hue, Saturation, Luminance) to work per colour channel. Lower the Hue of blue towards purple for a cooler blue. Increase the Luminance of yellow for brighter skin tones in portrait photos. Small per-channel adjustments give precision that a global colour slider cannot.

Color Grading (formerly Split Toning) lets you give shadows, midtones, and highlights each their own colour tint. The classic film-look treatment: warm tint in highlights, cool tint in shadows. That is the pattern you find in almost every well-made preset.