Add highcharts themes to a highchart object.
Examples
highchart() %>%
hc_add_series(
data = c(
7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2,
26.5, 23.3, 18.3, 13.9, 9.6
),
type = "column"
) %>%
hc_add_theme(hc_theme_sandsignika())