Color schemes in Vega/Vega-Lite/Altair
Some default color palettes are definitely nice looking and it is nice to be able to see the color codes together with a color sample. It is nice to be able to do that in Altair.
I don’t know whether it is possible to get the definition of the colors in Altair, but they are coded in the Vega source code here
import altair as alt
tableau20 = (
"4c78a89ecae9f58518ffbf7954a24b88d27ab79a20f2cf5b43989483bcb6"
"e45756ff9d9879706ebab0acd67195fcbfd2b279a2d6a5c99e765fd8b5a5"
)
colors = (
pd.DataFrame(
list(
"#" + tableau20[6 * i : 6 * i + 6]
for i in range(len(tableau20) // 6)
)
)
.rename(columns={0: "color"})
.assign(x=1)
)
(
alt.Chart(colors)
.mark_bar(height=20)
.encode(
alt.Y(
"color",
scale=alt.Scale(
domain=colors.color.values,
scheme="tableau20",
),
title=None,
),
alt.Color(
"color",
scale=alt.Scale(
domain=colors.color.values,
scheme="tableau20",
),
legend=None,
),
)
.properties(width=200, height=500, title="tableau20")
.configure_title(
font="Fira Sans",
fontSize=20,
anchor="start",
dy=-10,
)
.configure_axis(
labelFont="Inconsolata",
labelFontSize=16,
labelPadding=10,
)
.configure_view(stroke=None)
)