ruby – 从散列值排序的哈希中获取键数组

我有一个像这样的哈希

{"red" => 3, "blue" => 1, "yellow" => 3, "green" => 1, "black" => 4}

我想按照散列值的顺序排序并显示前三种颜色,即

["black", "red", "yellow"]

我试着做一些像sort_by {| x,y | h [x]< => h [y]}和max_by {| x,y | h [x]},但我只得到[“黑色”].你如何获得前三名？

作为变体：

h = {"green"=>1, "red"=>3, "yellow"=>3, "blue"=>1, "black"=>4}
h.sort_by{ |color, n| -n }.map(&:first).take(3) #=> ["black", "red", "yellow"]