All 89 bee plants
Honeysuckle pollen
Lonicera periclymenum
Muted yellow, in the yellow range.
FloweringJune to September
PollenFair
NectarTrace
SeasonSummer, Autumn
WhereHedgerow, Woodland, Garden
The nectar sits well beyond a honeybee's tongue, so it is the pollen they work it for.

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.