Your experiment is over and data has been collected. You now want to study your data results and make comparisons between the independent variable and the dependent variable.
For the example project, a color scale can be created in order to 
use numbers to measures to describe the results.
The scale shown indicates different colors but not necessarily the colors that you will observe in your experimental results.
I suggest that you create your own color scale.
Check out paint samples at a store that mix paint for specific colors. You find a color chart that could be used in designing the color scale for your investigation.
You can use your color scale to create a graph.
For more information about Data Analysis, see
SCIENCE FAIR PROJECTS: DATA ANALYSIS