The best colors for blonde hair and hazel eyes are the ones that choose a side, because hazel eyes next to light hair have nothing darker to anchor them and will copy whatever you wear. Moss and olive greens make them look greener. Camel, tobacco and toasted caramel make them look gold. Dusty plum sits between the two and works best on ash blonde. This page is about clothing, not hair color, and it splits the advice by what really changes the result: whether your blonde is golden or ash, and how deep your skin is.
Hazel eyes already shift between green, gold and brown depending on the light. With dark hair and dark lashes, that shift is limited, because the frame holds the iris steady. Blonde hair removes the anchor. The face is light all around the eye, so the iris becomes the darkest point and picks up the color of the garment under your chin. A sage green sweater and a camel coat can make the same person look like they have two different eye colors on the same day.
That is useful, but it means the neckline carries more weight than it would for a brunette. A color worn within a hand-width of your face is working as an eye filter, and a color worn below the waist is only part of the outfit. If you have blonde hair and hazel eyes, treat the top half as the place for your strongest color and let trousers, skirts and shoes be quieter. The strongest clothing colors for this pairing are mid-depth and slightly muted. Very bright colors compete with the iris, and very pale ones, like ice blue or optic white, make light hair and light eyes dissolve into one pale mass.
The shade of blonde decides the direction. Golden blondes, including honey and dark golden blonde, share warmth with the amber in hazel, so olive, moss and chocolate create a green contrast without losing harmony. Ash and beige blondes are cooler, and they look best in dusty plum, heather and muted teal, which sit opposite the gold. Skin depth then sets how much saturation you can handle. Very fair skin needs softer, more diluted versions of every shade, while light olive or tan skin can handle richer, deeper ones.