A gene on my StrateGene pathway is a single speed/color, however there are multiple SNPs on that gene with different speeds/colors. How do I know how fast or slow the enzyme is naturally?

The SNPs will each have their own individual speed listed, however, the total enzymatic speed is the combined SNPs overall impact on that gene.

For example, your ADOA2A gene may have a overall slow (purple) speed on the pathway, and in the "notable variation" section it will have one fast speedometer (orange), and two slow speedometers (purple). All together, these SNPs may have an overall impact of a slightly slow gene/enzyme, which would result in a purple gene/enzyme on the pathway. 

Keep in mind these are theoretical calculations and may not reflect in your life or clinically due to epigenetic factors.