Warning button disabled styling

[rowellx68]

Bug Report

What is the issue?

When adding both the nhsuk-button--disabled class and the disabled attribute to a warning button, the button's colour changes from red to green. This issue also occurs when we just use the disabled attribute. We expect this to behave like how it does when only the nhsuk-button--disabled is used.

What steps are required to reproduce the issue?

1. Create a warning button
2. Add the nhsuk-button--disabled class and disabled attribute

What was the environment where this issue occurred?

• Device: N/A
• Operating System: N/A
• Browser: N/A
• Browser version: N/A
• NHS.UK frontend package version: 8.3 and 9
• Node version: N/A
• npm version: N/A

Is there anything else you think would be useful in recreating the issue?