Do they make any other color filter paper circles other then white?
The most common color is white, although there are other colors available. Color filter paper circles are not really necessary in the industry that filter paper circles are used, which is why its so much easier to find them in white than in other colors. There are many different crafts that parents do with their kids where they color the filter paper circles themselves. This can be done by tie-dying, splatter paint or just by painting it all one color with an acrylic paint. They are then used for a certain holiday or event that they were painted to match (i.e. a green and red filter paper could be used to decorate the Christmas tree). Filter paper is a semi-permeable paper barrier placed perpendicular to a liquid or air flow. It is used to separate fine solids from liquids or air. They are most commonly used for oil and air in the automobile, and for coffee machines to make coffee to drink. Sources: http://en.wikipedia.
