Adding colour or fill to ggplot2 layer results in error in ggplotly

Question

When I pass my ggplot2-object to ggplotly() it throws a strange error;

Error in train(..., self = self) : unused argument (list("b", "a", "c"))

It seems to work if I omit the color/fill arguments from the layer - but that’s nit what I want. Does anybody else get this error, or is it just me? In the example below the error occurs when I pass ggp3 to ggplotly().

df <- data.frame(a = c(1:10), b = c(2010:2019), c = c(rep("a", 5), rep("b", 5)))


# as expected
ggp1 <- ggplot(data = df) +
  geom_point(aes(y = a,
                 x = b,
                 # color = c # without color
                 ))
ggp1

ggp1 %>% plotly::ggplotly()

# as expected
ggp2 <- ggplot(data = df) +
  geom_point(aes(y = a,
                 x = b),
                 color = "red") # with non aes color

ggp2

ggp2 %>% plotly::ggplotly()

# not as expected
ggp3 <- ggplot(data = df) +
  geom_point(aes(y = a,
                 x = b,
                 color = c)) # with color
ggp3

ggp3 %>% plotly::ggplotly()

Any help much appreciated!