Original Grey Technic motor from 1977: 6216a

[Jens Bauer]

Now that we have renumbered the parts, I can maybe be more clear.

I follow you completely now, yes - and I definitely agree.

6228a is Steffens 12V motor.
{snip} ... Isn't there any visual difference between them?

I think that the 12V motor has the same physical shape as the 4.5V motor (except from the "4V" text on some variants of the back).
Thus I think it'd be possible to leave the colour 'user configurable' and then just choose the motor's shape.
But I can also see why it would be desirable to make a 'harcoded' colour in the final 12V and the final 4.5V motor, since that would give the particular part the correct look.
(If someone would like to have a yellow motor, it's still possible to use the 'uncolored assembly' for that).