“The higher quality beeswaxes are bleached by purely physical methods – predominantly by adsorption of impurities (coloured and otherwise) onto activated carbon and/or diatomaceous earths and the like. The coloured impurities are thus removed and not available for reversion. So the beeswax should not darken with time (assuming proper storage – cool, dry, out of sunlight and away from any taints).

Lower quality beeswaxes, lightened by sunlight or washing, tend to leave behind some (colourless) impurities, that can later degrade to coloured entities.

The chains in beeswax are a bit more complex than those in plain paraffin waxes and can, on subsequent exposure to sunlight or heat, degrade to give some darkening. This is more the beeswax itself breaking down rather than any impurities re-colourising.

Although we describe some beeswaxes as “white”, at best they are a pale off-white (and when melted the liquid is quite yellow).” end quote from supplier

…. I found out myself and contacted a supplier of bleached beeswax..it is as I suspected the bleached or waxes that are not lightened by the sun and lightened chemicaly or such as is stated here should not return to yellow but the sun bleached ones will much like what happens with oils in paints
I have not given the supplier name as this is not spam it is information for genuine artists to read!

am not sure if it will yellow much more than it’s state on purchase ie years down the line I would be interested if anyone reading this could inform please. Please note am not referring to microcrystalline waxes they are petroleum based and a different thing together concerning natural waxes that is being refered to here