Create a new overline color attribute.
This attribute modifies the color of overlines. If not set, overlines will use the foreground color.
| red |
the red value (ranging from 0 to 65535) |
| green |
the green value |
| blue |
the blue value |
|
the newly allocated `PangoAttribute`, which should be freed with [method@Pango.Attribute.destroy] |