private Colour[] GetSelectedColours(string selection)
{
_inputValidator.ThrowExceptionWhenInputLengthIsNotFour(selection);
var selectedColours = new Colour[4];
var index = 0;
foreach (var character in selection)
{
var number = character - '0';
_inputValidator.ThrowExceptionWhenSelectedColourIsInvalid(number, Colours.Length);
selectedColours[index] = Colours[number - 1];
index++;
}
return(selectedColours);
}
