`element_geom(colour = "red")` does not work for lines

[davidhodge931]

library(tidyverse)

economics |>
  ggplot() +
  geom_line(
    aes(x = date, y = unemploy),
  ) +
  theme(geom.line = ggplot2::element_geom(colour = "red"))

^{Created on 2025-06-25 with reprex v2.1.1}

[davidhodge931]

Most of the other line geoms don't work

Interestingly, vline doesn't work, but hline does..

[yutannihilation]

Oh, curious.

library(ggplot2)

ggplot(economics) +
  geom_line(aes(date, unemploy)) +
  geom_vline(xintercept = as.Date("1990-01-01")) +
  geom_hline(yintercept = 10000) +
  theme(geom = element_geom(colour = "red"))

^{Created on 2025-06-25 with reprex v2.1.1}

Note that, I believe most of the result is intended. You can use ink to apply the theme colors. But, I'm not familiar with these concepts enough to explain what the design is. So, I might be wrong here.

ggplot2::GeomLine$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2

For consistency, maybe color should be removed from hline?

ggplot2::GeomVline$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2

ggplot2::GeomHline$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% ink)
#> env:  namespace:ggplot2

[davidhodge931]

I prefer not to use ink, because it changes the colour slightly, and I want to set the colour/fill unmodified..

[davidhodge931]

Looks like the defaults need to be changed for a lot of the line-ish geoms to ensure it prioritises colour when it is specified

These are the geoms I checked..

library(ggplot2)

#doesn't take colour
GeomContour$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomCurve$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomDensity2d$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% accent)
#> env:  namespace:ggplot2
GeomFunction$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomLine$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomLinerange$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomPath$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomRug$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomSegment$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomSpoke$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomStep$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomText$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% ink)
#> env:  namespace:ggplot2
GeomVline$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomContour$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2

#does take colour
GeomAbline$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% ink)
#> env:  namespace:ggplot2
GeomHline$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% ink)
#> env:  namespace:ggplot2
GeomErrorbar$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% ink)
#> env:  namespace:ggplot2
GeomQuantile$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% accent)
#> env:  namespace:ggplot2
GeomText$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% ink)
#> env:  namespace:ggplot2
GeomLabel$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% ink)
#> env:  namespace:ggplot2
GeomArea$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% NA)
#> env:  namespace:ggplot2
GeomBar$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% NA)
#> env:  namespace:ggplot2
GeomCol$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% NA)
#> env:  namespace:ggplot2
GeomTile$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% NA)
#> env:  namespace:ggplot2
GeomViolin$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% col_mix(ink, paper, 0.2))
#> env:  namespace:ggplot2
GeomBoxplot$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% col_mix(ink, paper, 0.2))
#> env:  namespace:ggplot2
GeomSpoke$default_aes$colour
#> <quosure>
#> expr: ^from_theme(ink)
#> env:  namespace:ggplot2
GeomDensity2d$default_aes$colour
#> <quosure>
#> expr: ^from_theme(colour %||% accent)
#> env:  namespace:ggplot2

^{Created on 2025-06-25 with reprex v2.1.1}

[yutannihilation]

Based on this discussion, it's probably by design? The geoms that can use ink directly is supposed to use ink. But, in polygon's case, since ink affects both lines and fills, it requires colour to override if the user want different colors for lines and fills.

#6347 (comment)

(I'm not necessarily against your opinion, but I'd like to figure out what the current consensus is)

[teunbrand]

I think it should contain fill = from_theme(fill %||% ink) and colour = from_theme(colour %||% ink) for typical unmixed values and I'm not sure why this wasn't included in #6285. Possibly, I could just have forgotten GeomPath whence the others inherit.

because it changes the colour slightly

This is only true for some geoms that have col_mix() in their defaults.

[yutannihilation]

Oh, thanks. I was wondering this was done on purpose.