Node-RED version: v1.0.1

Node.js version: v10.16.3

Dashboard version 2.17.0 started at /ui

I'm sending msg={topic:'RH',payload:45}; to a single line chart. The color of the line (payload) is now determined by the top middle box color.

Here's a dump of the saved output:

```
[{"series":["","RH"],"data":[[],[{"x":1571733636484,"y":47.57},{"x":1571733908802,"y":47.61},{"x":1571734176840,"y":47.43},{"x":1571734453500,"y":47.65},{"x":1571734725844,"y":48.01},{"x":1571735000379,"y":48.25},{"x":1571735272726,"y":48.24},{"x":1571735547240,"y":48.44},{"x":1571735819555,"y":48.57},{"x":1571736092987,"y":48.35},{"x":1571736364246,"y":48.2},{"x":1571736636588,"y":47.84},{"x":1571736908885,"y":47.34},{"x":1571737176765,"y":45.96},{"x":1571737445685,"y":44.74},{"x":1571737719033,"y":44.6},{"x":1571737991306,"y":44.93},{"x":1571738264677,"y":45.26},{"x":1571738531538,"y":45.7},{"x":1571738804934,"y":45.79},{"x":1571739078314,"y":46.13},{"x":1571739350614,"y":46.02},{"x":1571739621793,"y":46.31},{"x":1571775748456,"y":41.54},{"x":1571776016460,"y":42.12},{"x":1571776289893,"y":42.24},{"x":1571776562222,"y":43.35},{"x":1571776833339,"y":42.82}]],"labels":[""]}]
```