because if it wasnt....say it was black,pink,green, or so on....all of the colors wouldn't show on the paper.
Filter paper is white.
White
The simplest answer I can give for this is that not all paper is white. Construction and craft paper come in many colors, and if one wishes to draw a white object on said paper, they will need to color it in with white.
Paper of any colour other then white.
a monkey
Newsprint paper is typically light gray or off-white in color.
white paper can be printed from a printer to make it colour. in newspapers you see mostly black and white pictures
Paper Towels are bleached so they can be in color or print.
The color of the papyrus plant is mixed color of yellow, white and green. The color of papyrus paper is a mixed colour of white, yellow and brown.
If you stare at green paper for 30 seconds and then shift to white paper, you may see an afterimage of the complementary color, which is magenta. This phenomenon is known as color adaptation or color afterimage.
look at a piece of paper
Yes. (That's how they get it white.)