Color Mode Exercise
Selfie
RGB:

Index color:
The index color image has 10 colors because it is the color that I chose. The file size is one third of the original RGB image because it has less colors and that makes it smaller.
Greysale:
The greyscale image has 256 colors or shades of grey. The file size is one third of the original RGB image but it is the same as the index color image. It is way smaller that the RGB image because it does not have the same amount of colors.
Bitmap:

Prep Quiz
Can you change FILE FORMAT just by changing its name?
No, you can't change the file format like that because you will confuse the computer.
How many colors are in the following COLOR MODES?
RGB: 16.7 milion
INDEXED COLOR: 256 or less
Greyscale:256
BITMAP:2
What happens to the (uncopressed) FILE SIZE as you change the COLOR MODES?
The file size changes by the amount of colors you have in the image. If you put less colors the file size is going to be smaller.What happens to the visual quality of images as you REDUCE the number of colors by changing the color mode?
As you reduce the number of colors you also reduce the file size of the image and so you reduce the quality.What is a good reason to convert PSD files to JPG?
You change a file to JPG when you complete the image and it is ready to go online.