' Draw 10 Red Balloons each with a string
SCREEN 12     ' start up graphics
COLOR 4       ' set the pen color to red
'
LET BALLOON = 1              ' start with balloon number 1
DO WHILE BALLOON <= 10       ' end with balloon number 10
  LET X = BALLOON * 64 - 32  ' calculate an X for this balloon
  CIRCLE (X, 100), 25        ' draw a balloon
  LINE  (X, 125) - (X,225)   ' draw its string
  LET BALLOON = BALLOON + 1  ' go on to next balloon
LOOP
'
END

Changing Colors

Since the string is in the same column as the center of the circle, both the startX and the endX are the same value, the X of the balloon's center. Since the radius of the balloon is 25, the string should start 25 pixels down from the center:

The center:      (X, 100)
25 pixels down:  (X, 125)

Remember that Y increases going down. To make the string 100 pixels long, add 100 to the line's startY:

The start of the string:      (X, 125)
The end of the string:        (X, 225)

The balloon and string look like the following:

But the program so far draws both balloon and string in the same color (red, color number 4). Here is the program, again, but with some changes part way made so that the balloon is drawn with pen color number 4 (RED) and the string is drawn with pen color number 2 (GREEN):

' Draw 10 Red Balloons each with a GREEN string
SCREEN 12                    ' start up graphics
'
LET BALLOON = 1              ' start with balloon number 1
DO WHILE BALLOON <= 10       ' end with balloon number 10
  LET X = BALLOON * 64 - 32  ' calculate an X for this balloon
'
  COLOR ______               ' set the pen color to red
  
  CIRCLE (X, 100), 25        ' draw a balloon
'
  COLOR ______               ' set the pen color to green
  
  LINE  (X, 125) - (X,225)   ' draw its string
  LET BALLOON = BALLOON + 1  ' go on to next balloon
LOOP

END