Plotting range of columns

Hello, when I use the example from

using DataFrames, StatsPlots
df = DataFrame(a = 1:10, b = 10 .* rand(10), c = 10 .* rand(10))
@df df plot(:a, cols(2:3), colour = [:red :blue])

I get the error ArgumentError: unsupported symbol b passed to label Does anyone know what I am missing?

This appears to be fixed in an update