The Dimensions of Colour: Modern Colour Theory for Traditional and Digital Painting Media
by Dr David J.C. Briggs · huevaluechroma.com
A free, extensively illustrated treatment of colour written for painters in any medium, organising colour around hue, lightness, chroma and saturation. Readers finish able to reason about value and chroma precisely rather than relying on colour-wheel folklore.
More resources on Color Theory in Drawing
Composition Library
Master advanced composition techniques with Matt Kohr's Composition Library! Learn to create compelling art through proven visual principles.
Color and Light: A Guide for the Realist Painter
Explains how light reveals form and how pigments, atmosphere, and human perception shape what a painter sees. Covers light sources, colour relationships, and surface effects, so you can reason about a scene's colour instead of copying it.
drawabox.com
Drawabox is a structured drawing fundamentals resource offering free lessons, drills, and assignments that teach basic sketching from lines and shapes, covering construction, perspective, and form. It provides instructional videos and written guides to practice shading and improve accuracy.
line-of-action.com
Line of Action is a free drawing-practice site that provides a pose generator and photo references to help you practice gesture drawing. It offers timed sessions with customizable content—from human figures and hands to faces and animals—so you can build speed and accuracy.
Handprint Watercolor Color Theory
Bruce MacEvoy's long-form treatment of color grounded in colorimetry and vision science, covering additive and subtractive mixing, pigment behavior, and CIELAB. Readers come away able to critique the traditional artists' color wheel on physical grounds.
Colour Mixing with Pastels — Royal Drawing School Living Library
A free tutor-written exercise from the Royal Drawing School on optical mixing in chalk pastel, covering secondaries from layered primaries, complementary pairs, browns and coloured greys. Doing it teaches how pressure and layer order control the resulting hue.