Colour is one part of the response.
In a metallic–roughness material model, base colour, metalness and roughness work together. For non-metals, base colour describes diffuse colour. For metals, it colours the reflected light.
These parameters describe a material response; they are not a replacement for appropriate lighting, scale or geometry. Start with a clear reference for what the surface should look like.
Watch the reflection.
Lower roughness makes reflections sharper. Higher roughness spreads them. Watch the width of a highlight and the clarity of the environment reflected in the surface.
When comparing materials, keep the camera and lighting fixed. A different light source can change the highlight even when the material is unchanged.
Keep detail in proportion.
A normal map changes the local shading direction to suggest fine surface detail. It does not, by itself, change the silhouette of the object.
Think about texture scale as well as strength. A convincing weave at one distance can become distracting when the view moves closer. Check both the detail and the overall read.
A SMALL EXERCISE
Read the same surface twice.
Open the Materials comparison and move the divider. Look at the broad form first, then the fabric and timber. These approximate AI studies explain a visual idea; they do not isolate a single physical material parameter.
Explore the material studyA concept guide, not a tested LEMON setup tutorial. Rhino 9 workflows and supported settings will be documented after validation.