如何让ggplot2中stat_ellipse与geom_point用R brewer同色且椭圆黑边

我希望每个Pond分组的stat_ellipse椭圆填充色匹配geom_point使用的R brewer YlOrRd配色，且椭圆为黑色描边，但当前所有椭圆被黑色填充。

我的代码如下：

plot <- ggplot(plotpca, aes(x=PC1,y=PC2)) +
  geom_point(aes(fill=Pond),pch=21,size=3) +
  stat_ellipse(geom = "polygon",aes(group=Pond,color=Pond),alpha = 0.25, color="black") +
  scale_fill_brewer(palette="YlOrRd",aesthetics = c("color", "fill")) 
plot(plot)

绘图用的数据子集：

> dput(head(plotpca))
structure(list(PC1 = c(-0.0505964065450834, 0.0546247180570643, 
0.0385794513330037, -0.0421393543493591, 0.0284612585699651, 
0.0209291807114026), PC2 = c(0.0534548597921124, 0.00385797355835037, 
0.0217307675631555, -0.0319287619859987, -0.00204735494019053, 
-0.00709853162293151), group = structure(c(5L, 1L, 1L, 1L, 1L, 
1L), levels = c("LIL", "RHM", "SCS", "STN", "STS", "TS"), class = "factor"), 
    Pond = structure(c(6L, 4L, 4L, 4L, 4L, 4L), levels = c("RHM", 
    "TS", "SCS", "LIL", "STN", "STS"), class = "factor"), name = c("Ga0598233", 
    "Ga0598239", "Ga0598240", "Ga0598241", "Ga0598242", "Ga0598243"
    )), percentVar = c(0.570804459528504, 0.31299732413872), row.names = c("Ga0598233", 
"Ga0598239", "Ga0598240", "Ga0598241", "Ga0598242", "Ga0598243"
), class = "data.frame")

• 使用geom = "polygon"时，椭圆的填充色由fill美学控制，你当前仅在stat_ellipse中映射了color，且全局设置color="black"，导致填充色默认继承黑色。
• 虽然scale_fill_brewer指定了同时控制color和fill美学，但stat_ellipse未将fill绑定到Pond变量，配色规则无法生效。

library(ggplot2)
library(RColorBrewer)

plot <- ggplot(plotpca, aes(x=PC1, y=PC2)) +
  geom_point(aes(fill=Pond), pch=21, size=3) +
  stat_ellipse(geom = "polygon", aes(group=Pond, fill=Pond), 
               alpha = 0.25, color="black") +
  scale_fill_brewer(palette="YlOrRd") 
plot(plot)

1. 在stat_ellipse的aes中添加fill=Pond，让椭圆填充色与点的填充色绑定到同一分组变量，实现配色统一。
2. 保留color="black"作为椭圆的描边色，不再映射color=Pond，满足黑色描边的需求。
3. 移除scale_fill_brewer中的aesthetics = c("color", "fill")，因为仅需控制fill美学（点和椭圆的填充色），color已固定为黑色。

内容的提问来源于stack exchange，提问作者Geomicro