Copy of Additiveand Subtractive Colors SE PDF

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Name:

Manisha.G

Date:

March 17 2021

Student Exploration: Additive Colors Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: additive color, cyan, magenta, primary colors, RGB value, secondary color, visible spectrum Prior Knowledge Questions (Do these BEFORE using the Gizmo.) When white light passes through a prism, it splits into a rainbow of colors. These colors make up the visible spectrum shown below.

1. What is the order of colors in the visible spectrum? Red, Orange, Yellow, Green, Blue, Indigo and Violet. 2. What do you think would happen if all of the colors of light in the visible spectrum were blended together?

If all colours in the visible spectrum were blended together, I assume that it would make a white colour.

Gizmo Warm-up On a computer or TV screen, all the colors you see are mixtures of only three primary colors of light. In the Additive Colors Gizmo, you will explore how the primary colors can be mixed to make any color. 1. The primary colors are listed on the left side of the Gizmo. What are they?

Red, green and blue.

2. Check each box to turn each color on. Notice that the intensity of each color can be adjusted with the slider. What happens to the color if you move the slider to the left? When the slider is moved to the left the colour starts to become darker and then fade away. 3. Turn on Show RGB values at the mouse location, and move each slider to the right. The RGB value gives how much red, green, and blue light is in a given color. Move the cursor over each colored circle. List the RGB values of each pure color below. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

Red:

250

0

0

Activity A:

Green:

0

250

Blue:

0

0

250

Get the Gizmo ready: ● Set the Red, Green, and Blue values to 255.

Mixing light

Question: What happens when red, blue, and green light are mixed? 1. Predict: What color do you expect to be produced from each of the following light combinations? Red and green light:

Yellow.

Green and blue light:

Cyan

Red and blue light:

Purple

Red, green, and blue light:

White

2. Observe: Drag the red circle so that it overlaps with the green circle. What color is made by mixing red and green light?

It has made a yellow light colour.

3. Gather data: Try the remaining color combinations. Describe the resulting colors below. Red and blue light:

Combining both has resulted in a magenta colour light.

Green and blue light:

Combining both has resulted in a cyan colour light.

Red, green, and blue light:

Combining all colour lights has resulted in a white colour light.

4. Identify: A secondary color is produced when two primary colors are mixed. The names of the secondary colors are yellow, cyan (blue-green), and magenta (pinkish purple). Without using the Gizmo, name the numbered colors in the diagram at right, and predict the RGB value of each. Area

Color

RGB value

1

Yellow

250,250,0

2

Magenta

250,250,0

3

Cyan

0,250,250

4

White

250,250,250

After completing the table, check your answers by using the Gizmo. 5. Analyze: Colored lights are called additive colors. Why do you think this is so?

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I assume that coloured lights are called additive colours because of the wavelenghts in the lights. The different wavelengths create many colours which we see with our eyes.

Student Exploration: Subtractive Colors Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. [NOTE TO TEACHERS AND STUDENTS: This lesson was designed as a follow-up to the Additive Colors Gizmo. We recommend you complete that activity before this one.] Vocabulary: absorb, CMY value, complementary color, cyan, magenta, primary colors, reflect, RGB value, secondary color, subtractive color, transmit Prior Knowledge Questions (Do these BEFORE using the Gizmo.) A color printer can print any color by mixing three primary colors of ink: cyan (light blue), magenta (bright pink), and yellow. 1. What color do you think you would get if you mixed cyan and magenta?

Blue

2. What color do you think you would get if you mixed cyan and yellow?

Green

3. What color do you think you would get if you mixed magenta and yellow?

Red

Gizmo Warm-up We see objects when light from that object enters our eyes. Some objects produce their own light, while others transmit or reflect light. The Subtractive Colors Gizmo allows you to explore how light is absorbed and reflected by colored pigments such as paint. Three primary colors of light—red, green, and blue—combine to make white light. Turn on Show RGB values at the mouse location to see how much red, green, and blue is in each color. 1. Move the cursor over a white area. What is the RGB value of white?

The RGB value of white is 255,255,255

2. Move the cursor over the cyan circle. What is the RGB value of cyan?

The RGB value of cyan is 0,255,255

3. Assume the cyan circle is a painted spot that is illuminated by white light. Some of the white light is absorbed by the cyan pigment, and some is reflected into your eyes. A. What colors of light are reflected by the cyan spot?

Green and blue.

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B. What color of light is absorbed by the cyan spot?

Activity A:

Red is absorbed.

Get the Gizmo ready: ● Turn on the Cyan, Magenta, and Yellow circles. ● Check that each color value is set to 255.

Mixing primary colors

Question: What happens when cyan, magenta, and yellow pigment are combined? 1. Gather data: Move the cursor over the magenta and yellow spots. Record the RGB value of each pigment, and then state which colors are absorbed and reflected by each pigment. Pigment

RGB value

Reflected colors

Absorbed color

Cyan

0, 255, 255

Green, blue

Red

Magenta

255,0,255

Red,blue

Green

Yellow

255,255,0

Red,green

Blue

2. Observe: Secondary colors are created when two primary colors are mixed together. Which colors result from each of the following pigment combinations Cyan and magenta: Blue

Magenta and yellow:

Cyan and yellow: Green

Cyan, magenta, and yellow:

Red Black

3. Analyze: Consider the combination of cyan and magenta. A. What color of light does both cyan and magenta reflect?

They both reflect blue light.

B. What color results from mixing cyan and magenta pigment?

Results in blue.

C. What colors of light are absorbed by the combination of cyan and magenta pigment? (2 answers)

Red and green.

4. Summarize: Explain the result of each color combination based on the colors that each pigment absorbs and reflects. Cyan and yellow: Cyan and yellow both result in green. Cyan reflects green,blue and absorbs red. Yellow reflects red,green and absorbs blue. Magenta and yellow:

Magenta and yellow both result in red. Magenta reflects red,blue and absorbs green. Yellow reflects red,green and

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absorbs blue. Cyan, magenta, and yellow:

Cyan,magenta and yellow result in black. Cyan reflects green,blue and absorbs red. Magenta reflects red,blue and absorbs green. Yellow reflects red,green and absorbs blue. These secondary colours in a combination creates a black colour....