Eye drop colors are something that has always confused beginning ophthalmology residents. The eye drop bottle colors have been standardized, and you’ll almost always seen the same color for the same drop. Yes, there are sometimes exceptions (especially with generic manufacturers).

We’ve tabulated for you the most important classes of drops in an easy way.

Dilating drops – Red
Phenylephrine, tropicamide, atropine, cyclopentolate, cyclomydril

Combination drops with timolol – Blue
Dorzolamide-timolol (Cosopt), brimonidine-timolol (Combigan)

Alpha agonist – Purple
Brominidine (Alphagan)

Prostaglandin analogue – Turquoise
Latanoprost (Xalatan), travoprost (Travatan), bimatoprost (Lumigan)

Beta blockers – Yellow
Timolol (Timoptic), levobunolol (Betagan)
Betaxolol (Betoptic) – light blue top

Carbonic anhydrase inhibitors – Orange
Dorzolamide (Trusopt), brinzolamide (Azopt)

Antibiotics – Tan
Ofloxacin (Ocuflox), ciprofloxacin (Ciloxan), moxifloxacin (Vigamox, Moxeza), gatifloxacin (Zymar, Zymaxid), besifloxacin (Besivance)

Steroid – Pink or White
Prednisolone acetate (Pred Forte/Pred Mild), fluoromethalone (FML), rimexolone (Vexol), loteprednol (Lotemax), difluprednate (Durezol)

Topical NSAID – Gray
Ketorolac (acular, acuvail), diclofenac (Voltaren)

Topical anesthetics or steroids – White
Proparacaine, tetracaine

Generic medications, over-the-counter medications
Often don’t follow the official color guide

The AAO worked with the FDA to select the color combinations, which most pharmaceutical companies follow. See the article:

http://www.aao.org/about/policies/color-codes-topical-ocular-medications