Devtools Color: Drag to delete custom color in palettes

Source/devtools/front_end/elements/spectrum.css

 /* https://github.com/bgrins/spectrum */
 :host {
     width: 232px;
     height: 240px;
     -webkit-user-select: none;
 }
 
 :host(.palettes-enabled) {
     height: 271px;
 }
@@ skipping 191 matching lines @@
     display: inline-block;
     border-radius: 2px;
     margin: 6px;
     cursor: pointer;
 }
 
 .spectrum-palette > .spectrum-palette-color {
     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 {
     border-color: transparent;
 }
 
 .spectrum-palette > .spectrum-palette-color:not(.empty-color):hover {
     transform: scale(1.15);
 }
 
 .add-color-toolbar {
-    position: absolute;
-    right: 29px;
-    bottom: 5px;
+    margin-left: -3px;
+    margin-top: -1px;
 }
 
 .spectrum-palette-switcher {
     right: 10px;
     top: 235px;
     margin-top: 9px;
     position: absolute;
 }
 
 .palette-panel {
@@ skipping 69 matching lines @@
     width: 100%;
     height: 100%;
 }
 
 .spectrum-contrast-line {
     fill: none;
     stroke: white;
     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;
+}