Cracking the code in Colour Code, Games by Zaweba

Somewhere at the top of the board sits a row of coloured pegs, hidden from view. You have ten tries to work out exactly what it is. Colour Code, on the Puzzles shelf of Games by Zaweba, is a code-breaking game in the spirit of the classic peg board, and it is one of the purest tests of reasoning in the whole collection.

Reading the pins

Fill a row with coloured pegs and press Check. Beside your row, little pins appear. Each black pin means one of your pegs is the right colour in the right hole. Each white pin means one of your pegs is a right colour but in the wrong hole. The pins do not tell you which pegs they refer to, and that is the whole puzzle. You have to work it out from the pattern of guesses and answers as they build up down the board.

A row with no pins at all is useful too. It tells you none of those colours are in the code, which removes them from every later guess.

Classic and Hard

There are two ways to play. Classic hides 4 pegs chosen from 6 colours, with no repeats, so each colour appears at most once. Hard hides 5 pegs chosen from 8 colours, and colours may repeat. That second rule makes a real difference: in Hard, a single white pin might mean two of the same colour are in the code, and you cannot rule out doubles the way you can in Classic.

Start with Classic until the logic of the pins feels natural, then move up. Games by Zaweba keeps your best result for each mode separately, so a slower Hard game does not spoil your Classic record.

Entering your guesses

With the mouse, click a colour and it fills the ringed hole, or drag a colour straight to whichever hole you want. Click a peg twice to remove it. On the keyboard, the number keys 1 to 8 pick colours, the arrow keys move between holes, Backspace clears and Enter checks the row. Once you are used to it, the keyboard is the quicker way to play.

A sensible way to think

Your first guess is mostly about gathering information. In Classic, a row of four different colours tells you how many of those four are in the code. A second guess using the remaining colours tells you about the rest. After that, you are mostly working out positions.

From then on, make every guess fit what you already know. A guess that contradicts an earlier answer wastes a try. Before you press Check, look back up the board and ask whether this row could be the code given every set of pins so far. If it could not, change it.

When you are down to the last few tries, avoid the temptation to test one idea at a time. A guess that could be the answer and also separates the remaining possibilities is worth more than one that only answers a single question.

Next to Colour Code on the shelf

Colour Code sits with Number Place, Picture Grid, Hidden Mines and Switch Off, the logic puzzles of Games by Zaweba, where careful deduction beats speed. It is one of the shorter ones, so it suits a few minutes over a cup of tea. Press Esc to pause and F1 if you want the rules again. Like everything in the app, it runs offline with no adverts or account.