Default geom_ref_line colour to panel.grid.major

[jongbinjung]

Use the current theme's panel.grid.major color for geom_ref_line, which seems to be better than defaulting to "white".

I use this a lot with theme_bw(), and it's a bit annoying to specify colour = "grey92" everytime ...

[hadley]

That retrieves the default theme, not the theme of the current plot, so I don't think it's a good idea, unfortunately.

[jongbinjung]

Is there a way to use the theme is the current plot?

[hadley]

No, because it might be modified after you add this layer (this is a general draw back to the current design of ggplot2)