[EuiDataGrid] Fix inconsistent focus halo

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## [`main`](https://github.com/elastic/eui/tree/main)
 
+**Bug fixes**
+
+- Fixed a `EuiDataGrid` inconsistent color halo when focusing on the control columns by changing outline of class `euiButtonIcon` in `euiDataGridRowCell` and mixin `euiCustomControlFocused` [#5522](https://github.com/elastic/eui/pull/5522))
+
 **Breaking changes**
 
 - Changed `EuiSearchBar` to preserve phrases with leading and trailing spaces, instead of dropping surrounding whitespace ([#5514](https://github.com/elastic/eui/pull/5514))

src/components/datagrid/_data_grid_data_row.scss

@@ -122,6 +122,13 @@
       white-space: nowrap;
     }
   }
+
+  // Ensures focus halo color consistency in ButtonIcons inside of the grid
+  .euiButtonIcon {
+    &:focus {
+      outline: $euiFocusRingColor solid $euiFocusRingSize;
+    }
+  }
 }
 
 .euiDataGridRowCell__popover {

src/global_styling/mixins/_form.scss

@@ -344,13 +344,14 @@
   // Requires a selector to work with the Amsterdam outline styles
   @if ($amsterdamSelector) {
     + #{$amsterdamSelector} {
-      outline: $euiFocusRingSize solid currentColor;
+      outline: $euiFocusRingColor solid $euiFocusRingSize;
     }
 
     // Chrome
     &:focus-visible + #{$amsterdamSelector} {
       outline-style: auto;
       outline-offset: 3px;
+      outline: $euiFocusRingColor solid $euiFocusRingSize;
     }
 
     &:not(:focus-visible) + #{$amsterdamSelector} {