library("mxmaps")

data("df_mxstate")
df_mxstate$value = df_mxstate$afromexican / df_mxstate$pop * 100
mxhexbin_choropleth(df_mxstate, num_colors = 1,
                    title = "Percentage of the population that self-identifies as Afro-Mexican",
                    legend = "%")

You can use label_color if you want the state abbreviations in a different color than the default black.

library("viridis")
library("scales")

df_mxstate$value = df_mxstate$afromexican / df_mxstate$pop 
# Will show a warning, look at the municipio examples to see how to remove it
mxhexbin_choropleth(df_mxstate, 
                    num_colors = 1,
                    label_color = "white",
                    title = "Percentage of the population that self-identifies as Afro-Mexican",
                    legend = "%",
                    label_size = 3.8) +
  scale_fill_viridis("percentage", labels = percent)