The data and code for this question were adapted from:

How to fill colors of stacked bar plot depending on colors column of df in R using ggplot

I want to fix the order of country appearance in each stack so that “USA” is on the bottom and “Other” is at the top, but allow the colours associated with each country in each stack to change. The attempted code:

producer_countries <- 
    as.data.frame(tribble(~Country,    ~year,   ~total_value,  ~col,    
                          "USA",      1995,   100,        "green",
                          "China",    1995,   177,        "red",
                          "Other",    1995,   150,        "brown",
                          "USA",      2000,   100,        "red",
                          "China",    2000,   177,        "green",
                          "Other",    2000,   320,        "brown"))

ggplot(producer_countries, aes(fill=Country, y=total_value, x=year)) +     
    geom_bar(position="stack", stat="identity",  color = "black", aes(fill=col))+
    scale_fill_identity() +
    xlab("Year") +
    ylab("Quantity")

produces

But the ordering is by colour, i.e. red is always on the bottom, whereas I need the order to be green, red, brown in the left bar, and red, green, brown in the right bar.