Mixtures can be separated by chromatography, literally "colour drawing".
In our experiments we used filter paper to separate mixtures of coloured substances dissolved in water to show how it works.Click here for an animation.
However, you can use chromatography to separate mixtures that are not coloured, using different solvents, replacing the filter paper with things like silica gel.
You can have fun separating the dyes in felt pens. You might like to try these experiments at home, using blotting paper instead of filter paper.

Links
a helpful site