Overlaying histogram using rbokeh

Question

I am trying to create an overlaying histogram using rbokeh.

An example can be found below:

library(rbokeh)
# Simple approach:
h1 <- figure(width = 600, height = 400) %>%
            ly_hist(eruptions, data = faithful, breaks = 40, freq = T)

# Overlaying approach:
faithful$grouper <-  sample(c("A","B"), 272, replace = T)

h2 <- figure(width = 600, height = 400) %>%
            ly_hist(eruptions, data = faithful, breaks = 40, freq = T, color = grouper)

I am not sure whether the color option would provide this functionality.

Thanks for your help.