[CHORE] Update some theme colours

[taraepp]

Objective

Separating out changes to colours into its own PR

• Match mockups
• changes in webpack.parts affect how index-pure.less is compiled so it gets those sneaky class attributes
• generally I do like to use the color and bg-color class names instead of setting the style.color attribute, but I wanted to be absolutely sure I wasn't breaking anything.
• ScrollSidePageWrapper had the linter or sonarqube (I forget which) yelling at me when I opened it to get rid of the unused import and the ternary, so I did that.

Screenshots

Note that some of the changes here, like the text change from Needs Review --> Requires Review, are not included in this PR (images are to show colour changes)
(left = after, right = before)


new red: #D8292F, old red: #DF0D0D (not really noticeable!)
New yellow:

Old yellow:

[sonarqubecloud]

Quality Gate passed for 'bcgov-sonarcloud_mds_minespace-web'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed for 'bcgov-sonarcloud_mds_common'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
72.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed for 'bcgov-sonarcloud_mds_core-web'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud