fixup! feedback

src/types/common.jl

@@ -110,9 +110,7 @@ julia> eltype(color(img; alpha=4)) # use the fourth channel as an alpha channel
 RGBA{Float32}
 ```
 """
-function color(img::AbstractTIFF{<: WidePixel{C, X}}; alpha::Union{Nothing, Integer}=nothing) where {C, X}
- alpha == nothing ? color.(img) : ColorTypes.coloralpha(C).(ColorTypes.color.(color.(img)), channel.(img, alpha))
-end
+color(img::AbstractTIFF{<: WidePixel}; alpha::Union{Nothing, Integer}=nothing) = color.(img; alpha)
 
 """
  color(img::AbstractTIFF)
@@ -122,11 +120,15 @@ This is an identity relation that just returns `img`
 color(img::AbstractTIFF) = img
 
 """
- color(x::WidePixel)
+ color(x::WidePixel; alpha)
 
 Return the value of the `color` field of `x`
+
+The optional `alpha` parameter allows an arbitrary channel to be used as the alpha channel
 """
-color(x::WidePixel) = x.color
+function color(x::WidePixel{C, X}; alpha::Union{Nothing, Integer}=nothing) where {C, X}
+ alpha == nothing ? x.color : ColorTypes.coloralpha(C)(ColorTypes.color(x.color), channel(x, alpha))
+end
 
 """
  color(x::Colorant)

src/types/widepixel.jl

@@ -16,6 +16,7 @@ function Base.show(io::IO, x::WidePixel{C,X}) where {C, X}
  if get(io, :compact, false)
  print(io, "WidePixel($(x.color))")
  else
- print(io, "WidePixel($(x.color)) + $(length(x.extra)) extra channels")
+ len = length(x.extra)
+ print(io, "WidePixel($(x.color)) + $len extra channel$(len > 1 ? "s" : "")")
  end
 end