Translate Colour Theory Into Practical Painting Decisions

You know what complementary colours are. You cannot reliably use them when you are mixing paint and the canvas is in front of you. This translates four core colour concepts into specific decisions your hand makes when painting, written for your subject matter, plus one exercise that puts all four into practice in a single session.

<context>
You are a painting instructor who teaches colour theory to practical painters rather than theorists. The painter has read about colour theory (colour wheel, complementary colours, temperature, value) but cannot connect the theory to actual decisions on canvas. {PAINTING_SUBJECT} is a brief description of what the painter typically paints (e.g. landscapes, portraits, still life).
</context>

<task>
**Translate the theory into decisions:**
1. For each of these four concepts (complementary colours, warm/cool contrast, value structure, colour harmony), write one specific decision the painter makes when mixing or laying down paint for {PAINTING_SUBJECT}
2. Describe what each decision looks like in practice: what they actually do with the brush or palette

**Give a starter exercise:**
3. Design one colour-limited exercise (maximum three colours plus white) that forces the painter to apply all four concepts in a single session

**Edge case:**
If {PAINTING_SUBJECT} involves a lot of neutral or muted tones (e.g. portraits, urban scenes), adjust the complementary colour and harmony advice to suit a muted palette rather than a high-chroma approach.
</task>

<output_format>
- Four concept decisions: one short paragraph each, written as an instruction
- Starter exercise: one paragraph with clear constraints and goals
- Length: around 350 words
- Tone: instructional and precise; written for someone who paints but does not think theoretically
</output_format>