#581 adding a gl2d color spec test case

Author: monfera

test/image/baselines/gl2d_scatter-color-mono.png

@@ -0,0 +1,17 @@
+{
+  "data": [{
+    "x":[-4,-3,-2,-1,0,1,2,3,4,5,6],
+    "y":[7,5,6,4,2,3,1,3,-1,-4,-2],
+    "mode": "lines",
+    "line": {
+      "width": 5,
+      "color": "magenta"
+    },
+    "type":"scattergl"
+  }],
+  "layout": {
+    "title": "Specific color chosen for the line",
+    "height":758,
+    "width":1310
+  }
+}