Specifying the Color of Graph Elements in Julia Plots
Overview
In Plots.jl, the keywords for specifying the color of each graph component are as follows.
| Keyword | Function |
|---|---|
markercolor, mc | Specify the marker’s inside color |
markerstrokecolor, msc | Specify the marker’s border color |
linecolor, lc | Specify the line color |
fillcolor, fc | Specify the fill color |
seriescolor, c | Specify the color of all components |
| Keyword | Function |
|---|---|
markeralpha, ma, mα | Specify the marker’s inside transparency |
markerstrokealpha, msa, msα | Specify the marker’s border transparency |
linealpha, la, lα | Specify the line transparency |
fillalpha, fa, fα | Specify the fill transparency |
seriesalpha, a, α | Specify the transparency of all components |
Colors
In Plots.jl, the targets whose color can be changed are dots, lines, and areas. The keyword arguments for specifying each color are markercolor(=mc), linecolor(=lc), and fillcolor(=fc). The property specified by these keywords does not affect each other; hence, even if you input mc = :red after plotting a line graph, the line color will not apply as red. Indeed, checking the property of p = plot(rand(10), mc = :red) shows the following.
julia> p = plot(rand(10), mc = :red)
julia> p.series_list[1][:linecolor]
RGBA{Float64}(0.0,0.6056031611752245,0.9786801175696073,1.0)
julia> p.series_list[1][:markercolor]
RGBA{Float64}(1.0,0.0,0.0,1.0)
The color of the plotted line graph is still the default color, not red.
Thus, if you plot multiple subplots and specify colors with the three keywords above, each will be applied accordingly. If you color the dots (markers) in purple :purple, the line in dark green :darkgreen, and the area in sky blue :skyblue, it will look as follows.
st = [:line :scatter :barhist :steppre :scatterhist :bar]
x = rand(20)
y = repeat(x, outer = (1, length(st)))
plot(y, seriestype = st, layout = 6,
mc = :purple,
lc = :darkgreen,
fc = :skyblue
)
Transparency
The keyword for determining the transparency of a color is created by replacing color with alpha in the color specifying keyword name. It is also acceptable to use the Greek letter α directly.
Alternatively, you can input a color code that includes transparency, such as RGBA, into the color specifying keyword.
plot(rand(20, 3), layout = (3,1), seriestype = [:scatter :line :bar],
mc = :red,
lc = :green,
fc = :blue
)
plot(rand(20, 3), layout = (3,1), seriestype = [:scatter :line :bar],
markeralpha = 0.5, mc = :red,
la = 0.5, lc = :green,
fα = 0.5, fc = :blue
)
Environment
- OS: Windows11
- Version: Julia 1.9.4, Plots v1.39.0