All 89 bee plants
Winter clematis pollen
Clematis cirrhosa
Pale cream, in the cream / white range.
FloweringNovember to February
PollenMinor
NectarFair
SeasonAutumn, Winter
WhereGarden
A minor winter offering, worked only when the sun warms the wall.

Easy to mistake for these
Closest pollen colours in our set, measured the same way the pollen identifier scores a match. Colour alone will not settle it, so check the flowering months and what is actually growing near your hives.
Out at about the same time
Saw a load like this going in?
Sample the colour against all 89 plants, then keep a forage record per hive.