(Taken as a writing prompt, OP)
Their eyes are something more, something lost. Dim and bright all at once, like a candle-fire, rich and roasting brown. They are beyond warm - burning, even - and not a bit of fire resides in them.
There are so many colors to brown, you know, like flames and embers. There, at the rim of the iris, a rich red like glowing cinders rolling in their ashen bed. Spots of a deep grayish-blue, murky like the mud of a lake, flecked with flint and gold. Strands of green like leaves and creepers crawling among masses of branches and thorns, barbed and guarded, hiding something soft and lively and very warm indeed. If you look deeper - past fire and water and earth - you might find treasure; rubies and gold coins, glinting mischievously, alight with amusement and daring and cleverness.
These are daring eyes. This, a daring soul, and its windows are wine-dark and as rich as the flavor of char-broiled meat spun over open flame. Each one is as careful and curious as a fish’s ripple, and if you dare deeper, you can see the sky - a flaring orange halo ‘round the pupil, like the setting sun, and each woven thread beholding hues of eggplant purple, midnight blue, evening yellow and warming umber.
Some people say brown eyes are boring and dull, absent color. Those are the people who haven’t looked deeper - beneath all brown lie the possibility of a thousand rainbow hues.
In my eyes, I see a prism of color.