Highcharts is very flexible so you can modify every element of the chart. There are some exiting themes so you can apply style to charts with few lines of code.
Details
More examples and details in https://www.highcharts.com/docs/chart-design-and-style/themes.
Examples
hc <- highcharts_demo()
hc
thm <- hc_theme(
colors = c("red", "green", "blue"),
chart = list(
backgroundColor = "#15C0DE"
),
title = list(
style = list(
color = "#333333",
fontFamily = "Erica One"
)
),
subtitle = list(
style = list(
color = "#666666",
fontFamily = "Shadows Into Light"
)
),
legend = list(
itemStyle = list(
fontFamily = "Tangerine",
color = "black"
),
itemHoverStyle = list(
color = "gray"
)
)
)
hc_add_theme(hc, thm)