Black, white and greys in RGB
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which RGB value makes black?
2. Which RGB value makes white?
3. Which colour is a grey?
4. Which grey is darker?
5. What does (200, 200, 200) look like?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1rgb(0, 0, 0) | A255 for every value is white, not black. Black needs all values at 0. | |
| 2rgb(255, 255, 255) | Brgb(50, 50, 50) | |
| 3A mid grey has equal red, green and blue values, halfway between black and white | CThe values are not all equal. The lower blue value gives a yellowish tint instead of a pure grey. | |
| 4A darker grey uses smaller equal values than a lighter grey | DWhite: red, green and blue all at full strength | |
| 5rgb(200, 200, 100) for a light grey | EBlack: no red, no green and no blue light | |
| 6rgb(255, 255, 255) for black | Frgb(128, 128, 128) |
C
Definitions
rgb(r, g, b)
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
black = rgb(_, 0, 0)
2.
white = rgb(255, ___, 255)
3.
# Equal values make a grey
grey = rgb(128, ___, 128)
4.
darkGrey = ___(40, 40, 40)
5.
# Make blue bigger to tint the grey
tint = rgb(90, 90, ___)
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
black = (0, 0, 0)
B
white = (255, 255, 255)
C
dark_grey = (64, 64, 64)
D
light_grey = (192, 192, 190)
Question 2
A
text = rgb(0, 0, 0)
B
bg = rgb(255, 255, 255)
C
border = rgb(128, 128, 0)
Question 3
A
black = (0, 0, 0)
B
white = (255, 255, 0)
C
print(black, white)
Question 4
A
light = (200, 200, 200)
B
dark = (230, 230, 230)
C
print(light, dark)
Question 5
A
grey = (100, 100, 200)
B
r, g, b = grey
C
print(r == g and g == b)
Answer Key
Black, white and greys in RGB
Section A: Quick Questions
Q1
A — (0, 0, 0)
Q2
B — (255, 255, 255)
Q3
B — (128, 128, 128)
Q4
A — (40, 40, 40)
Q5
A — A light grey
Section B: Match the Pairs
Q1
rgb(0, 0, 0) → Black: no red, no green and no blue light
Q2
rgb(255, 255, 255) → White: red, green and blue all at full strength
Q3
A mid grey has equal red, green and blue values, halfway between black and white → rgb(128, 128, 128)
Q4
A darker grey uses smaller equal values than a lighter grey → rgb(50, 50, 50)
Q5
rgb(200, 200, 100) for a light grey → The values are not all equal. The lower blue value gives a yellowish tint instead of a pure grey.
Q6
rgb(255, 255, 255) for black → 255 for every value is white, not black. Black needs all values at 0.
Section C: Definitions
Q1
rgb(r, g, b) — Black is (0, 0, 0), white is (255, 255, 255). Any grey has equal red, green and blue values, like (128, 128, 128). Smaller equal numbers are darker; unequal numbers give a tint.Section D: Fill in the Blanks
Q1
black = rgb(0, 0, 0)Q2
white = rgb(255, 255, 255)Q3
# Equal values make a grey
grey = rgb(128, 128, 128)Q4
darkGrey = rgb(40, 40, 40)Q5
# Make blue bigger to tint the grey
tint = rgb(90, 90, 180)Section E: Spot the Error
Q1
D — A grey needs equal red, green and blue values. (192, 192, 190) has slightly less blue, so it is a tinted colour, not a true grey. It should be (192, 192, 192).
Q2
C — A mid grey needs all three values equal. With blue at 0 the colour turns olive-yellow. It should be rgb(128, 128, 128).
Q3
B — White needs red, green and blue all at the maximum, 255. With blue at 0 this is yellow. It should be (255, 255, 255).
Q4
B — Smaller equal numbers make a darker grey. (230, 230, 230) is lighter than (200, 200, 200), so the dark grey needs a smaller value such as (50, 50, 50).
Q5
A — A grey has equal red, green and blue values. Blue is 200 here, which gives a blue tint. It should be (100, 100, 100).