Added invertedColors

Issue #175

README.md

@@ -366,6 +366,7 @@ slide.addChart({MULTI_TYPES_AND_DATA}, {OPTIONS_AND_AXES});
 | `chartColorsOpacity` | number | percent | `100` | data color opacity percent         | 1-100. Ex: `{ chartColorsOpacity:50 }` |
 | `fill`          | string  |         |           | fill/background color              | hex color code. Ex: `{ fill:'0088CC' }` |
 | `holeSize`      | number  | percent | `50`      | doughnut hole size                 | 1-100. Ex: `{ holeSize:50 }` |
+| `invertedColors`| array   |         |           | data colors for negative numbers   | array of hex color codes. Ex: `['0088CC','FFCC00']` |
 | `legendFontSize`| number  | points  | `10`      | legend font size                   | 1-256. Ex: `{ legendFontSize: 13 }`|
 | `legendPos`     | string  |         | `r`       | chart legend position              | `b` (bottom), `tr` (top-right), `l` (left), `r` (right), `t` (top) |
 | `layout`        | object  |         |           | positioning plot within chart area | object with `x`, `y`, `w` and `h` props, all in range 0-1 (proportionally related to the chart size). Ex: `{x: 0, y: 0, w: 1, h: 1}` fully expands plot to the chart area |