Is that not what 'blonde' generally is in adults? An image search for 'blonde man' returns men I'd consider 'blonde' which hair which seems objectively light brown (except those with obviously bleached highlights.)
The color of Augustus here[0] is definitely blonde for me, bordering on platinum, while what I meant is that it might as well have been darker, i.e. [1] which I would call "light chestnut".
