Operation Manual

A beginner’s guide to Scratch
76
The computer can display
256 x 256 x 256 colours.
That’s 16,777,216
different colours!
Try making up your own colours.
>>> PiColour = (123,456,789)
>>> surface.ll(PiColour)
>>> pygame.display.update()
Argh! Now that wasn’t fun. You created a bad colour and Python has told you
(in American).
TypeError: invalid color argument
You will have to watch for American spellings like these when writing commands
to computers, as a lot of computing standards are developed in the USA.
Python is telling you that the colour tuple is not valid. The PyGame documentation
says that the colour tuple must only have values from 0 to 255. Each number
represents how much red, green or blue you want in the colour (in that order).
Mixing these will give you every colour that the computer can display. That’s
256 x 256 x 256 different colours. Try typing this at the prompt to get the answer
to that product.
>>> 256 * 256 * 256
Or even:
>>> 256 ** 3
The symbols ** mean “raised to the power of”. Notice that I haven’t used “print()”.
Python can be a great calculator, too!
Notes: