Plots.jl contour line colors

Specific Domains Visualization
1

When using contour (not contourf) with Plots.jl, is there a way to force all the contour lines to be a single fixed color?

2 
contour(rand(10, 10), color=:blue)
3

Seems to be broken with the PyPlot backend:

MethodError: no method matching get_colorscheme(::RGBA{Float64})
Closest candidates are:
  get_colorscheme(::PlotUtils.AbstractColorList) at ~/.julia/packages/PlotUtils/NE7U1/src/colorschemes.jl:4
  get_colorscheme(::AbstractVector{<:Colorant}) at ~/.julia/packages/PlotUtils/NE7U1/src/colorschemes.jl:303
  get_colorscheme(::AbstractVector) at ~/.julia/packages/PlotUtils/NE7U1/src/colorschemes.jl:304
  ...

Stacktrace:
  [1] cgrad(::RGBA{Float64}; kwargs::Base.Pairs{Symbol, Nothing, Tuple{Symbol}, NamedTuple{(:alpha,), Tuple{Nothing}}})
    @ PlotUtils ~/.julia/packages/PlotUtils/NE7U1/src/colorschemes.jl:244
  [2] py_linecolormap(series::Plots.Series)
    @ Plots ~/.julia/packages/Plots/SkUg1/src/backends/pyplot.jl:255
  [3] py_add_series(plt::Plots.Plot{Plots.PyPlotBackend}, series::Plots.Series)
    @ Plots ~/.julia/packages/Plots/SkUg1/src/backends/pyplot.jl:600
  [4] _before_layout_calcs(plt::Plots.Plot{Plots.PyPlotBackend})
    @ Plots ~/.julia/packages/Plots/SkUg1/src/backends/pyplot.jl:1034
  [5] prepare_output(plt::Plots.Plot{Plots.PyPlotBackend})
    @ Plots ~/.julia/packages/Plots/SkUg1/src/plot.jl:218
  [6] show(io::Base64.Base64EncodePipe, m::MIME{Symbol("image/png")}, plt::Plots.Plot{Plots.PyPlotBackend})
    @ Plots ~/.julia/packages/Plots/SkUg1/src/output.jl:201
  [7] base64encode(::Function, ::MIME{Symbol("image/png")}, ::Vararg{Any}; context::Nothing)
    @ Base64 /Applications/Julia-1.7.app/Contents/Resources/julia/share/julia/stdlib/v1.7/Base64/src/encode.jl:209
  [8] base64encode
    @ /Applications/Julia-1.7.app/Contents/Resources/julia/share/julia/stdlib/v1.7/Base64/src/encode.jl:206 [inlined]
  [9] _ijulia_display_dict(plt::Plots.Plot{Plots.PyPlotBackend})
    @ Plots ~/.julia/packages/Plots/SkUg1/src/ijulia.jl:44
 [10] display_dict(plt::Plots.Plot{Plots.PyPlotBackend})
    @ Plots ~/.julia/packages/Plots/SkUg1/src/init.jl:91
 [11] #invokelatest#2
    @ ./essentials.jl:716 [inlined]
 [12] invokelatest
    @ ./essentials.jl:714 [inlined]
 [13] execute_request(socket::ZMQ.Socket, msg::IJulia.Msg)
    @ IJulia ~/.julia/packages/IJulia/AQu2H/src/execute_request.jl:112
 [14] #invokelatest#2
    @ ./essentials.jl:716 [inlined]
 [15] invokelatest
    @ ./essentials.jl:714 [inlined]
 [16] eventloop(socket::ZMQ.Socket)
    @ IJulia ~/.julia/packages/IJulia/AQu2H/src/eventloop.jl:8
 [17] (::IJulia.var"#15#18")()
    @ IJulia ./task.jl:429

Simple
4

It works by feeding a singleton array of colours:

using Plots; pyplot()
contour(rand(10, 10), c=[:blue])