How to colour-code subjects in your study plan

Step 1 — colour means subject, and nothing else

The most common mistake is loading two meanings onto one colour. If red means "maths" and also "urgent", then every red dot costs you a moment of working out which one it is. At that point the colour has stopped being information and become decoration.

Attach colour to the subject only. Other axes — urgency, how far along something is — belong on a different control. In Plannote, progress already lives in the four states (to do, in progress, done, later), which frees colour to answer exactly one question: which subject is this?

Step 2 — get down to five to seven subjects

Having eight colours available is not a reason to use eight. People reliably distinguish roughly five to seven colours at a glance. Past that you start consulting a mental legend every time you look, which is barely better than having no colours at all.

Grouping like this usually lands you inside that range.

• Give each high-stakes subject its own colour (English, maths, whichever ones your exams actually weigh).
• Merge subjects of the same character into one colour (physics, chemistry and biology → 'science'; history and geography → 'humanities').
• Put all the non-studying items on a single colour — forms to hand in, a course to pay for, admin.
• Leave a colour or two unused. You'll want somewhere to put a subject that appears mid-term.

Step 3 — don't assign the colours arbitrarily

Which colour goes to which subject can also be decided in a way that pays off later. Two rules are enough.

• Give the loudest colour to the subject you study most. If maths is half your day, maths should be the first thing your eye lands on.
• Push easily-confused subjects far apart on the colour wheel. Two subjects that always appear together shouldn't both be blue-ish.
• Reuse any association you already have. Matching the textbook cover or your highlighter means there's nothing to memorise.
• Once set, don't change them mid-term. The value of a colour comes entirely from it always being the same.

Step 4 — know where the colour actually gets read

Once assigned, the colour shows up in three places in Plannote. In the task list, each item carries a 4dp colour bar down its left edge, so you can tell the subject of a row without reading its title.

In the month calendar, every date gets a dot for each subject scheduled that day. Spread a month out and the lopsided weeks jump out — and so do the weeks where one colour is simply absent. "I haven't done English in two weeks" is invisible when you page through lists one day at a time; it's obvious as a gap in the dots.

Under the dots sits that day's completion bar. The colours say what you planned, the bar says how much of it you did. With both in the same cell, finding the weeks that were all plan and no execution takes seconds.

Step 5 — group recurring subjects by weekday

Once the gaps are visible, the next friction is retyping the same items every week. Anything fixed — vocabulary on Mon/Wed/Fri, a Sunday review block — can be created as a weekday repeat, which generates twelve weeks of it from the weekdays you pick.

Do that and the colour distribution on your calendar takes on a regular shape by itself, which means a week that fell apart stands out as a break in the pattern. You stop needing a separate ritual to check whether you're following the plan.

If the colours drift, none of this survives

When a colour system collapses, it's usually not the user's fault. Planner reviews are full of lines like "I set a different colour for each subject and now they've all become the same colour" — which happens in apps where the colour isn't really attached to the subject but recomputed by some other rule. Once they merge, all four steps above are worthless.

In Plannote the colour is assigned to the subject and stays there. Pick from the eight and the bar in the list and the dots on the calendar keep showing that colour; two subjects never quietly merge into one shade. If you intend to read your plan by colour, that's the precondition.