ggplot2: facet_wrap strip color based on variable in data set

Question

Is there a way to fill the strips of facets created with facet_wrap based on a variable supplied with the data frame?

Example data:

MYdata <- data.f

Answer 1

It's not directly for differently coloring your facets but here you have another (very quick and simpler) solution, based on facet by two variables (size ~ fruit) instead one (~ fruit):

ggplot(data = MYdata, aes(x = farm, y = weight)) + 
  geom_jitter(position = position_jitter(width = 0.3), 
      aes(color = factor(farm)), size = 2.5, alpha = 1) + 
  facet_wrap(size ~ fruit)