Can I put an orange button on a petrol background?
No. On petrol, the primary action turns white, with petrol text.
Orange on petrol reads 2.27:1, below the 3:1 a component needs against its surface. White on petrol reads 10.27:1, and the action keeps its place and weight.
What this answer rests on
principles/colour.md§ The interactive orange Acceptedprinciples/colour.md§ Figure-ground: a fill against its surface Acceptedconstitutional/accessibility-is-foundational.md§ 1. The non-negotiables Accepted