It's common to have compartments that organize your pill schedule, usually with 14 labeled cells - morning and evening for each day of the week.

Set it up once a week and then just take the pills in the appropriate cell when the time is right. This also solves the problem of "did I already take my pills for today?".

I saw those compartment sheets recently. They aren;t really widely used in my country.

It's a good memory aid, since most (all?) memory is associative in nature. Just coming UP with that system kept the neurons active some, if even a little.

But pills already don’t have unique colours.

There are other attributes as well - the combination of colour, size, shape and surface features might be unique in many people's mixes.

They aren't different colors. They have are a standard color with a standard sprinkle, but the details of the sprinkle are unique, like a (real) fingerprint.