All 89 bee plants
Gorse pollen
Ulex europaeus
Pale lemon, in the yellow range.
FloweringAll year, peak spring
PollenGood
NectarNone
SeasonWinter, Spring, Summer, Autumn
WhereMoor and heath, Waste and verge
Flowers in some form in every month. A reliable standby when the calendar is quiet.

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.