Using colours to detect patterns

It might be helpful to colour all the candidates for a certain symbol, say all the 5's, or to mark groups of cells using colours. The program has options for both of these techniques.

Colouring candidates

The File menu has an option "Colour/uncolour candidates" for this purpose. Selection of the option produces a cascading menu of the symbols 1-9 and the user drags down to make a choice.

All candidates of the selected symbol will be set to the current colour. If the user later selects the same symbol from this menu its colour will be switched off and all the candidates for this symbol will have their colour status toggled. That is, those that are coloured will be uncoloured and those that are uncoloured will be coloured. How can some be coloured and some not? Well, the middle mouse button can be used to toggle the colour status of individual buttons. At present there are 5 arbitrary colours available, so up to 5 symbols could each be given a different colour at any time.

Undo will remove all colouring.

Set candidate colour

The candidate colour is set by a File menu option "Set candidate colour" which produces a cascading menu of colours from which the user drags down to make a selection.

The selected colour will then be used in all "Colour candidates" choices until the user changes the colour through this option.

Colouring cells

Some types of pattern might be thought about more easily by colouring particular cells. See Figure 1.

Each cell menu has an option "Colour/uncolour cell" which, if selected, will change the background colour of the cell. If the cell has already been "coloured" by this process, its colour will be switched off, otherwise it will be set to the current cell colour. i.e. it is another toggling process.

Set cell colour

The cell colour is set by a File menu option "Set cell colour" which produces a cascading menu of colours from which the user drags down to make a selection. The selected colour will then be used in all "Colour/uncolour cell" choices until the user changes the colour through this option. Figure 2. shows how this is done for candidates.