Colour is a signal, not decoration
A pink column looks nice — until you want to compare it with a blue one next to it and both are equally “just nice”. Colours in a chart should say something: good vs bad, income vs spend, yours vs the class average.
A data label is a number right by the column. A teacher does not have to guess the height — they see 3 at once.
Colours and labels step by step
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A chart from
Grades(A1:B6). Click the chart → editor → Series → column colour. Pick one colour for all grades (for example blue). Not five different colours — that looks like confetti. -
Turn on Data labels → show Value. By each column you will see 1, 2 or 3. Check that it matches the table.
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On
Pocketmake a column chart of only column C (Spent). Colour red or orange — spend “leaves”. Data labels: the value in Kč (you already have cell format). -
On a snack survey leave the biggest column stronger — in the editor click only one column (click twice), change the colour. Leave the others lighter. Did a roll win? That column darker.
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Leave the chart title. Do not turn on data labels on a pie with five small slices — they overlap. On a column chart yes.
Fewer colours = a more readable chart. One colour for one series. Two colours only when you compare In and Spent. A class with colour blindness? Do not rely only on red vs green — add data labels.
Labels vs a legend
A legend says what a series is. A label by a column says how many. With grades a label 2 by the Maths column is enough — you do not have to write “Maths: 2” when axis X already says Maths.
On a pie a label sometimes shows a percent and a count: editor → Labels → Value and percent. With 22 votes you will see 8 (36 %).
What often goes wrong
Five colours on five subjects. It looks like an advert. One colour, number labels.
Labels without format. On pocket money you will see 20 instead of 20 Kč. Format first in the table, then the chart.
A crowded pie. Labels on every slice overlap. On a pie leave a legend, turn labels off.
🏫 Grade average — highlight a problem
A subject with grade 3 — a darker column or orange. The others light blue. At a glance you see where to talk with a teacher. Leave average 1.8 in a cell under the table, not in chart labels.
💰 Pocket money — red spend
A spend chart: red columns, labels 15 Kč, 0 Kč… The day with the biggest column is the day money ran away most. Compare with an In chart (green) — two colours, two series, legend on.
📊 Class survey — the winner
The biggest column (a roll?) darker. Label 8 by it. Under the chart into a cell write a sentence: Most votes: roll (8 of 22). A picture + a sentence = a hand-in.
🏆 Mini dashboard — calm colours
A dashboard is not a disco. A grades chart: one colour, labels on, a clear title. Loud colours tire a teacher. Readability > effect.
Now you 💪
First: a grades chart — one colour, value labels, a problem subject highlighted.
Second: a spend chart from pocket money — red columns, labels in Kč.
Check: Each column has a number by it. Colours make sense, not chance. The pie is not crowded with labels.
What to take from this lesson
- One series = one colour. Two series = two colours + a legend.
- Data labels on a column chart save guessing.
- Highlight an important column with colour, not five different colours.
© 2026 Ing. Martin Polak / AlgoRhino · 内容使用条款