MethodError: no method matching coloralpha(::Type{RGB24})

[guo-yong-zhi]

coloralpha(ARGB(1,1,1,1)) is ok,
but coloralpha(ARGB32(1,1,1,1)) has error:

MethodError: no method matching coloralpha(::Type{RGB24})
Closest candidates are:
coloralpha(::C) where C<:TransparentColor at C:\Users\momos.julia\packages\ColorTypes\7OlxI\src\conversions.jl:140
coloralpha(::C, ::Any) where C<:TransparentColor at C:\Users\momos.julia\packages\ColorTypes\7OlxI\src\conversions.jl:141
coloralpha(::C) where C<:Color at C:\Users\momos.julia\packages\ColorTypes\7OlxI\src\conversions.jl:138

[kimikage]

This is simply because the type RGBA32 is not defined in ColorTypes.jl.

You can define it on your own.
cf. https://github.com/JuliaGraphics/ColorTypes.jl/blob/87364c41644c2fbea5aa7cb049cef15a4afb279f/test/customtypes.jl#L66-L77
However, non-parametric types like ARGB32 are not well supported in some packages.

You can also submit a PR to add an error hint in ColorTypes.jl.