Amber, blue or clear

What the shelf actually holds

Forty bottles qualify for this use, every one of them glass, from 100 to 946 ml. Nineteen of the forty block light: fourteen amber, four blue and one frosted amber. The other twenty-one are clear. That is a real choice with a real consequence rather than a styling preference.

Why light matters more here than elsewhere

Because there is nothing else protecting the product. A pickle has acid and a syrup has sugar; an oil has the bottle. Of the four things that age an oil, light is the only one the container removes rather than merely slows, which makes it the cheapest shelf-life improvement available.

Amber and blue are not equivalent

Both reduce light reaching the product and they do it across different parts of the spectrum, with amber generally the more complete barrier. Blue is often chosen because of how it looks on a shelf, which is a legitimate reason as long as it is the reason rather than an assumption that any colored glass is the same.

When clear is the right answer anyway

When the product is meant to be looked at and will be sold and used quickly: a tasting size, a market stall, a bottle with visible botanicals that are part of the appeal. The trade is explicit rather than hidden, and a shorter honest date goes with it.

Where the bottle sits is part of the decision

A clear bottle in a dark cupboard is fine and a clear bottle in a lit shop window is not. You control one of those and not the other, which is the argument for the dark bottle on anything going to retail.

References