In molecular modeling, different colors are usually used to represent different chemical elements.
The default color schemas used by different molecular graphics applications vary but there are some common themes. The typical color assignments are as follows:
Element | Color |
---|---|
H (hygroden) | White |
C (carbon) | Black |
N (nitrogen) | Blue |
O (oxygen) | Red |
Here is a ball-and-stick model that uses this coloring scheme:
And the full coloring palette used by the Wikipedia contributor Ben Mills: