fill only working for geom_boxplots if fill variable is the same length as x variable

[cldougl]

>dat <- data.frame(cond = factor(rep(c("A","B","C","D"), each=200)), col = factor(rep(c("C1","C2"), each=400)), rating = c(rnorm(200),rnorm(200, mean=.8),rnorm(200, mean=.4), rnorm(200, mean=.2)))
>ggplot(dat, aes(x=cond, y=rating)) + geom_boxplot(outlier.shape = NA, aes(fill=col))

from r:

shows up in plotly as

>dat <- data.frame(cond = factor(rep(c("A","B","C","D"), each=200)), col = factor(rep(c("C1","C2","C3","C4"), each=200)), rating = c(rnorm(200),rnorm(200, mean=.8),rnorm(200, mean=.4), rnorm(200, mean=.2)))
>ggplot(dat, aes(x=cond, y=rating)) + geom_boxplot(outlier.shape = NA, aes(fill=col))

but 4 colors will work in plotly for this chart