改變顏色GGPLOT2

Question

我用繪製在彼此的頂部的兩個柱狀圖如下：

library(ggplot2) 
library(reshape2) 


x = c("type1", "type2", "type3") 
y1 = c("1","2","3") 
y2 = c("2","3","4") 

to_plot <- data.frame(x=x,y1=y1,y2=y2) 
melted<-melt(to_plot, id="x") 

ggplot() + geom_bar(data=melted,aes(x=x,y=value,fill=variable),stat="identity",position = "identity", alpha=.3) 

這給了我下面的輸出：

反正我有可以改變條形圖的顏色嗎？例如，我想Y1圖是一樣的灰色作爲背景

Answer 1

ggplot() + geom_bar(data=melted,aes(x=x,y=value,fill=variable), 
        stat="identity",position = "identity", alpha=.3) + 
    scale_fill_manual(values=c("#955599", "#E63F00")) 

現在，您可以用調色板（玩 - ;