[One Discover] Update log.level indicators color (#202985)

## 📓 Summary

Closes #202258 

This change updates the colors scale for Discover's `log.level`
indicators to differentiate errors from other levels better.

**N.B. As this relies on some hard-coded values defined
[here](https://github.com/elastic/kibana/issues/186273#issuecomment-2505817075),
it is not a definitive version, but a middle step to enhance the scale
in v8.x versions.**
With the introduction of the Borealis theme in v9, a new scale
token-based will replace this.

<img width="934" alt="Screenshot 2024-12-04 at 17 40 32"
src="https://github.com/user-attachments/assets/b3da1300-b39a-4ad0-92c9-fde5dabe91ec">

---------

Co-authored-by: Marco Antonio Ghiani <marcoantonio.ghiani@elastic.co>

packages/kbn-discover-utils/src/data_types/logs/utils/get_log_level_color.test.ts

@@ -13,7 +13,9 @@ import { LogLevelCoalescedValue } from './get_log_level_coalesed_value';
 
 const euiTheme = {
   colors: {
-    lightShade: '#ffffff',
+    vis: {
+      euiColorVisGrey0: '#d3dae6',
+    },
   },
 };
 
@@ -32,20 +34,20 @@ describe('getLogLevelColor', () => {
       '#d6bf57'
     );
     expect(getLogLevelColor(LogLevelCoalescedValue.error, euiTheme as EuiThemeComputed)).toBe(
-      '#df9352'
+      '#e18774'
     );
     expect(getLogLevelColor(LogLevelCoalescedValue.critical, euiTheme as EuiThemeComputed)).toBe(
-      '#e7664c'
+      '#dd7b67'
     );
     expect(getLogLevelColor(LogLevelCoalescedValue.alert, euiTheme as EuiThemeComputed)).toBe(
-      '#da5e47'
+      '#d76f5b'
     );
     expect(getLogLevelColor(LogLevelCoalescedValue.emergency, euiTheme as EuiThemeComputed)).toBe(
-      '#cc5642'
+      '#d2634e'
     );
     // other
     expect(getLogLevelColor(LogLevelCoalescedValue.trace, euiTheme as EuiThemeComputed)).toBe(
-      '#ffffff'
+      '#d3dae6'
     );
   });
 });

packages/kbn-discover-utils/src/data_types/logs/utils/get_log_level_color.ts

@@ -7,7 +7,12 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-import { EuiThemeComputed, euiPaletteForTemperature, euiPaletteForStatus } from '@elastic/eui';
+import {
+  EuiThemeComputed,
+  euiPaletteForTemperature,
+  euiPaletteForStatus,
+  euiPaletteRed,
+} from '@elastic/eui';
 import { LogLevelCoalescedValue } from './get_log_level_coalesed_value';
 
 export const getLogLevelColor = (
@@ -16,8 +21,11 @@ export const getLogLevelColor = (
 ): string | undefined => {
   const euiPaletteForTemperature6 = euiPaletteForTemperature(6);
   const euiPaletteForStatus9 = euiPaletteForStatus(9);
+  const euiPaletteRed9 = euiPaletteRed(14);
 
   switch (logLevelCoalescedValue) {
+    case LogLevelCoalescedValue.trace:
+      return euiTheme.colors.vis.euiColorVisGrey0;
     case LogLevelCoalescedValue.debug:
       return euiPaletteForTemperature6[2]; // lighter, closer to the default color for all other unknown log levels
     case LogLevelCoalescedValue.info:
@@ -27,15 +35,16 @@ export const getLogLevelColor = (
     case LogLevelCoalescedValue.warning:
       return euiPaletteForStatus9[4];
     case LogLevelCoalescedValue.error:
-      return euiPaletteForStatus9[5];
+      return euiPaletteRed9[9];
     case LogLevelCoalescedValue.critical:
-      return euiPaletteForStatus9[6];
+      return euiPaletteRed9[10];
     case LogLevelCoalescedValue.alert:
-      return euiPaletteForStatus9[7];
+      return euiPaletteRed9[11];
     case LogLevelCoalescedValue.emergency:
+      return euiPaletteRed9[12];
     case LogLevelCoalescedValue.fatal:
-      return euiPaletteForStatus9[8];
+      return euiPaletteRed9[13];
     default:
-      return euiTheme.colors.lightShade;
+      return euiTheme.colors.vis.euiColorVisGrey0;
   }
 };

x-pack/test_serverless/functional/test_suites/observability/discover/context_awareness/_get_row_indicator_provider.ts

@@ -85,9 +85,6 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       const firstColorIndicator = await firstCell.findByTestSubject(
         'unifiedDataTableRowColorIndicatorCell'
       );
-      expect(await firstColorIndicator.getComputedStyle('background-color')).to.be(
-        'rgba(190, 207, 227, 1)'
-      );
       expect(await firstColorIndicator.getAttribute('title')).to.be('Debug');
     });
 
@@ -105,18 +102,12 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
         'unifiedDataTableRowColorIndicatorCell'
       );
       expect(await anchorColorIndicator.getAttribute('title')).to.be('Debug');
-      expect(await anchorColorIndicator.getComputedStyle('background-color')).to.be(
-        'rgba(190, 207, 227, 1)'
-      );
 
       let nextCell = await dataGrid.getCellElement(1, 0);
       let nextColorIndicator = await nextCell.findByTestSubject(
         'unifiedDataTableRowColorIndicatorCell'
       );
       expect(await nextColorIndicator.getAttribute('title')).to.be('Error');
-      expect(await nextColorIndicator.getComputedStyle('background-color')).to.be(
-        'rgba(223, 147, 82, 1)'
-      );
 
       await browser.refresh();
       await PageObjects.header.waitUntilLoadingHasFinished();
@@ -127,18 +118,12 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
         'unifiedDataTableRowColorIndicatorCell'
       );
       expect(await anchorColorIndicator.getAttribute('title')).to.be('Debug');
-      expect(await anchorColorIndicator.getComputedStyle('background-color')).to.be(
-        'rgba(190, 207, 227, 1)'
-      );
 
       nextCell = await dataGrid.getCellElement(1, 0);
       nextColorIndicator = await nextCell.findByTestSubject(
         'unifiedDataTableRowColorIndicatorCell'
       );
       expect(await nextColorIndicator.getAttribute('title')).to.be('Error');
-      expect(await nextColorIndicator.getComputedStyle('background-color')).to.be(
-        'rgba(223, 147, 82, 1)'
-      );
     });
   });
 }