在这种情况下，如何更改geom_point的颜色？

Question

以下是代码：

df$ProsperRating..Alpha.<-ordered(df$ProsperRating..Alpha., 
                                  levels = c("AA","A","B","C","D","E","HR"))
ggplot(aes(x=BorrowerAPR,y=LP_InterestandFees),
       data=subset(df,!is.na(ProsperRating..Alpha.)))+
  geom_point(alpha=0.2,aes(color=ProsperRating..Alpha.),position = "jitter")

以下是结果情节：

但我需要将这些点的颜色改为蓝调，如下所示：

我如何实现这一目标？

Answer 1

library(ggplot2)

qplot(x, price, data = diamonds, colour = clarity) +
  scale_colour_brewer(palette="Blues", direction = -1)

产生这个