Plastic color
Usually, if you see white or off-white plastic, that is virgin plastic.
Recycled plastic isn't sorted much color wise - except for sometimes clear plastic that is seperated.
Clear plastic can be recycled to clear plastic.
Most colored plastic is recycled into recycling granules that are just what ever color comes out.
You'd have to bleach plastic to get the pigment out, and that usually changes material properties even worse.
The wild mix of colours results in darker and darker results - so you often just add pigment to a dark shade to hide any inconsistencies.
Some additives can change colour aswell - and if you already have recycled plastic, adding the pigment isn't much cost and gives at least some idea of consistency if a consumer should ever open the top.
So if parts are a muddled, grey, black, brown or a very dirty shade of off-white, it is usually recycled plastic.
But even the use of recycled plastic has come far since a decade ago, and since the tub is structural in many designs (carrys bearings) they used to use virgin plastic.
But today, in some machines, they use recycled plastic for the outer tub.