# Changing the colours

When the program starts, each of the 18 predefined tiles has a unique colour which is used whenever that tile is added to the screen. You can change this colour by clicking on the coloured arrow to the right of the icon and selecting a new colour from the colour picker. The icon changes colour accordingly but the tiles which you have already positioned do not change - the new colour only controls the colour of the subsequent tiles.

Just below the 'hand' icon at the top of the toolbox there is a small square which displays the 'current colour'. Whenever you select a new tile, this square reflects the colour of the tile. In addition, you can change the 'current colour' independently using its own colour picker.

So when can you use the 'current colour'? The answer is by RIGHT-clicking on an existing tile. This changes the colour of the tile to the 'current colour'. Using this method, you can pick out certain groups of tile in a bold or cntrasting colour to make certain features of the tiling clearer.

Penrose tilings can be overprinted with spots and curly lines to indicate which combinations of tiles are permitted and which are not. The three check boxes at the bottom of the toolbox switch the 'spots', the 'thin' and the 'thick' lines on and off. In addition, the coloured arrow to the right allows you to change the colours. Note that, unlike the colours of each tile, the colours of the spots and lines are applied globally.