我正在尝试用ggplot制作grouped boxplots。我的代码生成了分组的箱线图。但是，有很多东西我想在箱线图上改进：

1）删除scale_fill_manual引入的第二个图例
2）保留代码中的颜色，更改箱线图，使其看起来像以下设计：

用我的代码生成的箱线图确实具有上述透明度，但是须状线穿过了箱形图（看起来不太好）。median应该像上面的示例一样可见，并且须状线不应该穿过箱形图。
以下是我到目前为止所尝试的。双重图例是一个问题，胡须穿过箱线图是另一个问题。
样本数据和代码：

library(ggplot2)
    ## create some data.frames: this results in a list of four dfs
    createDF <- quote(data.frame(id=sample(c("NN", "SS","H"), 100, rep=T),
                                 heavy=runif(100),
                                 heavier=runif(100),
                                 heaviest=runif(100)))
    dfs <- lapply(1:4, function(i) eval(createDF))
    
    ## join and shape them
    library(reshape2)
    dat <- do.call(rbind, dfs)
    dat$dfid <- paste("df", rep(1:4, times=sapply(dfs, nrow)))
    dat <- melt(dat, id.vars=c("id", "dfid"))
    
    #-----plot
    
    ggplot(dat, aes(x = factor(id, level = c('H', 'NN', 'NS')), y=value, group=interaction(variable, id), fill=variable, colour=variable)) +
      stat_boxplot(geom ='errorbar', width = 0.6,lwd = 0.9,position = position_dodge2(preserve = "single"))+
      geom_boxplot(aes(fill=variable, colour=variable),width = 0.6,lwd = 0.9,outlier.shape = NA,outlier.colour = NULL, coef = 0, 
                   position = position_dodge2(preserve = "single"),alpha = 0.6,fatten = 2) +
      coord_cartesian(ylim = c(0, 1))+
      scale_y_continuous(limits = c(0, 1), breaks = seq(0, 1, by = .25),expand = c(0, 0)) + 
      facet_grid(.~dfid)+ #reorder facets
      scale_fill_manual(values=c("#4daf4a","#984ea3","#ffff99","#ff7f00","#e41a1c"),name="")+ #  scale_fill_manual(values = c('1' = "black", '2' = "white", '3' = "darkred", '4' = "lightblue"))
      scale_color_manual(name = "scenario", values = c("#4daf4a","#984ea3","#ffff99","#ff7f00","#e41a1c"))+
      labs(y = "Values", x = "")+
      theme_bw()+
      theme(strip.text.x = element_text(size = 14, colour = "black", angle = 0, face = "bold"),
            axis.text = element_text(size = 12, color = "black"),
            text = element_text(size = 18),
            axis.text.x = element_text(angle = 0, hjust = 0.5, size = 9, colour = "black", face = "bold"),
            legend.direction = "vertical",
            legend.position = "right",
            panel.background = element_rect(fill = "grey70"),
            panel.border = element_rect(colour = "black", fill=NA, size=1))+
      theme(legend.direction ="vertical",legend.position = c(0.5, .79))+
      guides(fill=guide_legend(nrow=1))+ theme(legend.title = element_blank())+theme(legend.text = element_text(colour="black", size = 10, face = "bold"))+
      theme(legend.margin=margin(-10, 0, 0, 0))+
      theme(panel.grid.major = element_line(colour="white", size = 0.2),
            panel.grid.minor = element_blank())
    #theme(plot.margin = unit(c(0,0.0,0,0.2), "lines"))