[3920] Fix DateTime widget default style not set

Bug: #3920
Signed-off-by: Michaël Charfadi <[email protected]>

CHANGELOG.adoc

@@ -79,6 +79,7 @@ As a result, the following maven modules have been deleted: `sirius-web-sample-a
 - https://github.com/eclipse-sirius/sirius-web/issues/3878[#3878] [diagram] Unmount ReactFlowProvider after layout
 - https://github.com/eclipse-sirius/sirius-web/issues/3869[#3869] [form] Close form-based views when the underlying element no longer exists.
 - https://github.com/eclipse-sirius/sirius-web/issues/3899[#3899] [diagram] Fix an issue when using alt-tab shortcut and trying to drag a node afterwards
+- https://github.com/eclipse-sirius/sirius-web/issues/3920[#3920] [form] Fix DateTime widget default style not set
 
 === New Features
 

packages/view/backend/sirius-components-view-form/src/main/java/org/eclipse/sirius/components/view/form/adapters/FormColorAdapter.java

@@ -221,5 +221,16 @@ public Void caseTextfieldDescriptionStyle(TextfieldDescriptionStyle object) {
             }
             return null;
         }
+
+        @Override
+        public Void caseDateTimeDescriptionStyle(DateTimeDescriptionStyle object) {
+            if (object.getBackgroundColor() == null) {
+                object.setBackgroundColor(this.colorPaletteService.getColorFromPalette(object, "transparent"));
+            }
+            if (object.getForegroundColor() == null) {
+                object.setForegroundColor(this.colorPaletteService.getColorFromPalette(object, "theme.palette.text.primary"));
+            }
+            return null;
+        }
     }
 }