从ggplot2中的命名列表为气泡图分配自定义颜色

Question

在此处跟随一些代码示例 （ggplot bubble graph custom colors）  将命名列表中的颜色分配给气泡图，但无济于事。尝试从gapminder包中模拟country_colors功能。 颜色不是我提供的命名列表中所需的颜色。

 df <- data.frame(
      author = c("Atrhur", "Chloe", "Ernest", "Christian",
                 "Beth", "Wilson"),
      revenue = c(13796557L, 898702L, 15049136L, 28821608L, 44409616L, 21912235L),
      sold = c(492L, 62L, 548L, 38L, 182L, 879L)
    )

    mycolors <- structure(c("#7F3B08", "#833D07", "#873F07", "#8B4107", "#8F4407", 
                "#934407"), .Names = c("Atrhur", "Chloe", "Ernest", "Christian", 
                                       "Beth", "Wilson"))

    p <-
      ggplot(
        data = df,
        aes(
          x = revenue,
          y = sold,
          label = author
        )
      ) +
      geom_point(aes(size = revenue, alpha = 0.75, fill = author)) +
      scale_size_continuous(range = c(2, 20)) +
      geom_text_repel(segment.color = "gray") +
      theme(legend.position = "none") +
      scale_fill_manual(values = mycolors)
    p