Look
Set the project finish
Open Settings → Look. Choose the project's finish there. Keep this separate from the colours and material of an individual Stack or Shape. Use the Brand Kit for the project's Ground, Surface, Ink and Accent roles.
For a Stack, open Colours and Material. The Lit · Glass surface in Settings → Look changes the project surface. A custom element material can override the automatic material choice. For a device, inspect the body finish and screen brightness separately. Grade an image or video in Colour Grade rather than changing all project colours to correct one source.
Preview the result with the intended lights, background and render settings. A material colour and the colour of a rendered surface may differ under lighting.