#1542 Base theme for simple custom themeing

src/diagrams/er/styles.js

@@ -1,5 +1,18 @@
-const getStyles = () =>
+Base theme for cusom themeingconst getStyles = options =>
   `
+  .entityBox {
+    fill: ${options.mainBkg};
+    stroke: ${options.nodeBorder};
+  }
+
+  .relationshipLabelBox {
+    fill: ${options.edgeLabelBackground};
+    fillopactity: 0;
+    background-color: ${options.edgeLabelBackground};
+      rect {
+        opacity: 0.5;
+      }
+  }
 `;
 
 export default getStyles;