Index - O
| one | Chart.Data, Chart |
| opac | Data.Colour, Chart |
| opac' | Data.Colour, Chart |
| Orientation | Chart.Primitive, Chart |
| Origin | Data.Path.Parser, Chart |
| OriginAbsolute | Data.Path.Parser, Chart |
| OriginRelative | Data.Path.Parser, Chart |
| outerGap | Chart.Bar, Chart |
| OuterPos | Chart.Data, Chart |
| overText | Chart.Primitive, Chart |