first to understand what exactly shall be done:

Is this the correct behavior ?

• col can either be a Color((r,g,b)) or a Color((r,g,b,a))
• col = Color() returns a new Color((r=0, g=0, b=0, a=1))
• col = Color((0,0,0)) returns a new Color((r=0, g=0, b=0))
• col = Color((0,0,0,0)) returns a new Color((r=0, g=0, b=0, a=0))
• col = col.rgb() returns a new Color((r=0, g=0, b=0))
• col = Color.rgb() returns a new Color((r=0, g=0, b=0))
• col.has_alpha() returns True if col has 4 elements
• col.a gives a tracedump when col has no alpha

• Object.data.vertex_colors[].data is a list of Color((r,g,b,a)) items
• Object.data.vertex_colors[n].data[m] is a Color((r,g,b,a))

Are the above assumptions all correct?
What else is needed on the Python side ?
Is there anything to be done in addition ?

One thing is: How do i make a Color with optional 4th component?
Is there an example code somewhere so i can learn what to do here?

@Gaia Clary (gaiaclary). this is much closer to how I think it should work.

Minor changes.

• Color() shouldn't have alpha.
• col.rgb can be an attribute, like vec.xyz. rgb Should not return new colors, it should return RGB components of the color instance.
• has_alpha can be a readonly attribute. (we could also just check len(color) == 4).
• operations between colors with/without alpha should be supported but error in the case rgb/rgba are mixed.