The Go package colornames contains the list of color names.
The color names have taken from https://github.com/meodai/color-names.
// Find the longest color name and its color value.
var name string
var index int
for i := 0; i < colornames.N; i++ {
v := colornames.Get(i)
if len(v) > len(name) {
name = v
index = i
}
}
c := colornames.RGB(index)
fmt.Println(c.Hex(), name)