feat(theme): improved color contrast with color palette (#28791)

Issue number: Internal

---------

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issue. -->

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

The team would like to ensure that Ionic Framework components that use
an Ionic color (primary, secondary, etc) on top of a contrast color pass
minimum contrast ratios as defined in the WCAG.

## What is the new behavior?
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this PR. -->

- Introduces a revised set of Ionic colors that pass AA color contrast
guidelines when with the appropriate contrast.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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  2. Update the BREAKING.md file with the breaking change.
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## Other information

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screenshots of how the component looks before and after the change. -->

---------

Co-authored-by: Sean Perkins <13732623+sean-perkins@users.noreply.github.com>
Co-authored-by: Brandy Carney <brandy@ionic.io>
Co-authored-by: Sean Perkins <sean@ionic.io>
Co-authored-by: Shawn Taylor <shawn@ionic.io>
Co-authored-by: Brandy Carney <brandyscarney@users.noreply.github.com>
Co-authored-by: Amanda Johnston <90629384+amandaejohnston@users.noreply.github.com>
Co-authored-by: Maria Hutt <thetaPC@users.noreply.github.com>
Co-authored-by: ionitron <hi@ionicframework.com>

core/src/components/label/test/a11y/label.e2e.ts

@@ -1,3 +1,4 @@
+import AxeBuilder from '@axe-core/playwright';
 import { expect } from '@playwright/test';
 import { configs, test } from '@utils/test/playwright';
 
@@ -83,6 +84,30 @@ configs({ directions: ['ltr'] }).forEach(({ title, screenshot, config }) => {
   });
 });
 
+configs({ directions: ['ltr'], modes: ['md'], themes: ['light', 'dark'] }).forEach(({ title, config }) => {
+  test.describe(title('label: a11y for ion-color()'), () => {
+    test('should not have accessibility violations when focused', async ({ page }) => {
+      /**
+       * All page content should be contained by landmarks (main, nav, etc.)
+       * By containing the badge in a main element, we can avoid this violation.
+       */
+      await page.setContent(
+        `
+          <main>
+            <div class="ion-focused">
+              <ion-label position="stacked">Default Label</ion-label>
+            </div>
+          </main>
+        `,
+        config
+      );
+
+      const results = await new AxeBuilder({ page }).analyze();
+
+      expect(results.violations).toEqual([]);
+    });
+  });
+});
 configs({ modes: ['ios'], directions: ['ltr'] }).forEach(({ title, screenshot, config }) => {
   test.describe(title('label: text wrapping in item'), () => {
     test('long text should not cause label to expand infinitely', async ({ page }) => {