Fix ipywidgets dark mode for toolbar buttons on Colab (#1716)

* Fix ipywidgets dark mode on Colab

* Change button color for Colab only

geemap/toolbar.py

@@ -139,6 +139,10 @@ def returned_callback(change):
             layout=widgets.Layout(height="28px", width="72px"),
         )
 
+        if in_colab_shell():
+            self.toolbar_button.button_style = "primary"
+            self.layers_button.button_style = "primary"
+
         self.toolbar_header = widgets.HBox()
         self.toolbar_header.children = [self.layers_button, self.toolbar_button]
         self.toolbar_footer = widgets.VBox()
@@ -835,6 +839,10 @@ def search_data_gui(m, position="topleft"):
     )
     search_type.style.button_width = "110px"
 
+    if in_colab_shell():
+        search_button.button_style = "primary"
+        search_type.button_style = "primary"
+
     search_box = widgets.Text(
         placeholder="Search by place name or address",
         tooltip="Search location",