填充图例R阴影

Question

plot(1:4, 1:4, type="n", xaxt="n", xlab="", yaxt="n", ylab="")
polygon(c(2,4,2), c(1,3,3), col="gray")
polygon(c(3,3,1), c(1,3,2), col="red", density=10)
legend("topleft", legend=c("A", "B", "AB"), fill=c("gray", "red", "gray"),
       density=c(NA, 10, NA), bty="n",border=c("black", "red", "black")) 
legend("topleft", legend=c("A", "B", "AB"), fill=c("gray", "red", "red"),
       density=c(NA, 10, 10), bty="n", border=c("black", "red", "black"))

这不起作用。我想在传说中画出一个我想要的颜色的正方形。左border=c("black", "red", "black"))理论上这句话可以让我改变那种颜色。

  

图例错误（“topright”，图例= c（“TBR”，“TBF”，“标准”，   “命中”），：参数8匹配多个正式参数