更改ggplot在geom_bar中绘制边框颜色的顺序

Question

df <- data.frame(Taxon=c("A", "B", "C"),
                 Counts=c(0.1,0.5,0.4),
                 Treatment=rep("X1",3),
                 Effect=factor(c("A","B","A")))
df$Effect <- factor(df$Effect, levels=c("A","B"), ordered=T)

ggplot() + 
  geom_bar(data=df, aes(x = Treatment, y = Counts, fill = Taxon, colour=Effect), 
           stat="identity", position="fill", width=0.5)+
  scale_fill_manual("",values=c("gold", "green","yellow"))+
  scale_color_manual("",values=c("black","red"))

我想突出显示效果类型的所有“Taxon”周围带有红色边框的效果“B”。但ggplot似乎按照df$Taxon的顺序绘制矩形，而不是我希望通过首先应用分配给df $ Effect == A的颜色，然后df $ Effect == B.同样的情况也是如此。改变df $效果的顺序。

df$Effect <- factor(df$Effect, levels=c("B","A"), ordered=T)


ggplot() + 
  geom_bar(data=df, aes(x = Treatment, y = Counts, fill = Taxon, colour=Effect), 
           stat="identity", position="fill", width=0.5)+
  scale_fill_manual("",values=c("gold", "green","yellow"))+
  scale_color_manual("",values=c("black","red"))

当我想在表达效果“B”的分类词周围总是有完整的红色矩形时，如何对此进行编码？