Devtools Color: Drag to delete custom color in palettes

Source/devtools/front_end/elements/spectrum.css

Index: Source/devtools/front_end/elements/spectrum.css
diff --git a/Source/devtools/front_end/elements/spectrum.css b/Source/devtools/front_end/elements/spectrum.css
index 1a680d3b9e5cdc354032e6521f16411a0367ca92..63397da210be3ec30d6d9d81180776f92981840e 100644
--- a/Source/devtools/front_end/elements/spectrum.css
+++ b/Source/devtools/front_end/elements/spectrum.css
@@ -209,6 +209,7 @@
     transition: transform 100ms cubic-bezier(0, 0, 0.2, 1);
     border: 1px solid rgba(0, 0, 0, 0.1);
     will-change: transform;
+    z-index: 13;
 }
 
 .spectrum-palette > .spectrum-palette-color.empty-color {
@@ -220,9 +221,8 @@
 }
 
 .add-color-toolbar {
-    position: absolute;
-    right: 29px;
-    bottom: 5px;
+    margin-left: -3px;
+    margin-top: -1px;
 }
 
 .spectrum-palette-switcher {
@@ -312,3 +312,36 @@ div.palette-preview {
     opacity: 0.7;
     stroke-width: 1.5px;
 }
+
+.delete-color-toolbar {
+    position: absolute;
+    right: 0;
+    top: 0;
+    height: 100%;
+    background-color: #EFEFEF;
+    visibility: hidden;
+    z-index: 3;
+    width: 36px;
+    display: flex;
+    align-items: center;
+    padding-left: 5px;
+}
+
+@keyframes showDeleteToolbar {
+    from {
+        opacity: 0;
+    }
+    to {
+        opacity: 1;
+    }
+}
+
+.delete-color-toolbar.dragging {
+    visibility: visible;
+    animation: showDeleteToolbar 100ms 150ms cubic-bezier(0, 0, 0.2, 1) backwards;
+}
+
+.delete-color-toolbar-active {
+    background-color: #ddd;
+    color: white;
+}