enh(theming): RGBY contrast

[Pytal]

• For [BITV] 9.1.4.3/1.1 - The error message "Incorrect username or password" does not meet the contrast requirements for text - it is 4.3:1. (1) #36949

Summary

Existing --color-[error|warning|success|info] variables are currently used for various borders, icons, and text

They have been adjusted to meet the minimum 3:1 contrast ratio for “Graphical Objects and User Interface Components”, see https://webaim.org/resources/contrastchecker/

New variables --color-[error|warning|success|info]-text are added for text which meet the minimum 4.5:1 contrast ratio on light #ffffff and dark #171717 backgrounds

Contrast

/* contrast ratio on light background #ffffff */
:root {
  --color-error: #e9322d;        /* 4.23 */
  --color-error-text: #e7201b;   /* 4.55 */
  --color-warning: #c28900;      /* 3.06 */
  --color-warning-text: #996c00; /* 4.67 */
  --color-success: #3fa857;      /* 3.02 */
  --color-success-text: #318344; /* 4.71 */
  --color-info: #006aa3;         /* 5.85 */
  --color-info-text: #006aa3;    /* 5.85 */
}

/* contrast ratio on dark background #171717 */
:root {
  --color-error: #e9322d;        /* 4.23 */
  --color-error-text: #ea403b;   /* 4.52 */
  --color-warning: #c28900;      /* 5.87 */
  --color-warning-text: #c28900; /* 5.87 */
  --color-success: #3fa857;      /* 5.93 */
  --color-success-text: #3fa857; /* 5.93 */
  --color-info: #006aa3;         /* 3.07 */
  --color-info-text: #0088d1;    /* 4.65 */
}

Screenshots

	Screenshot
Before
After

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[artonge]

Code looks good