Update error colour

[ulde01]

Design decision 2021-06-16
This was actually decided a while back but I wanted some clarification before logging it.

Change

• New colour for both error text and indication: #9F000A

Reason

The colour for error texts and indications (i.e. the line, box, etc) have been updated to achieve the appropriate contrast value when presented on white or grey backgrounds.

Thank you!
(And as always, close this issue with a comment if it's not relevant)
/Ulrika