The_Official_Raspberry_Pi_-_Beginner’s_Book_Vol1,_2018 (1)

162 THE OFFICIAL RASPBERRY PI BEGINNER'S GUIDE

5 Figure 7-8: Changing the colour of the message and background

If you want to use friendly names instead of RGB values to set your colours, you’ll need to

create variables. Above your sense.show_message() line, add the following:

yellow = ( 255 , 255 , 0 )

blue = ( 0 , 0 , 255 )

Go back to your sense.show_message() line and edit it so it reads:

sense.show_message("Hello, World!", text_colour=(yellow), back_

colour=(blue), scroll_speed=( 0. 05 ))

Click the Run icon again, and you’ll see nothing has changed: your message is still in yellow

on a blue background. This time, though, you’ve used the variable names to make your code

more readable: instead of a string of numbers, the code explains what colour it’s setting. You

can define as many colours as you like: try adding a variable called ‘red’ with the values 255, 0,

and 0; a variable called ‘white’ with the values 255, 255, 255; and a variable called ‘black’ with

the values 0, 0, and 0.

As well as being able to scroll full messages, you can display individual letters. Delete your

sense.show_message() line altogether, and type the following in its place:

sense.show_letter("Z")