Different Line Colours on Chart based on a Third Variable

[boiledbeans]

This project is actually a continuation of previous discussed here.
http://www.excelforum.com/excel-gene...-formulas.html

But since it's a completely unrelated issue now, I've started a new thread.

In the attached file, I have plotted
Column A (Flow rate) on y axis
Column B (Amplitude) on x axis

Column C is the frequency.
I would like a different colour on the chart based on the frequency.
For example, row 3 to 17, should be a different colour from row 18 to 33 because the frequency is changed from 65535 to 25000.
So all 65535s would have a colour, while all 25000s would have another colour, etc.

If this is not possible, is there some other way to identify the frequencies on the chart?

The values at columns A, B and C may be changed in future so it would be good to have an automated system to plot the chart instead of plotting each section manually with a different colour.

Here is some background information:
The relationship between amplitude and frequency is like a bicycle with a larger front and smaller rear set of gears.
As you cycle faster, firstly, the smaller set of rear gears (amplitude) needs to be increased.
Once it reaches its max, the larger gear (frequency) needs to be adjusted, with the smaller gear (amplitude) reduced to the lowest again.
So this explains the jagged chart in the attachment.

So the aim of this chart is something like finding the optimal ratios for the 2 gears (frequency & amplitude) for various speeds (flow rate)

Thanks in advance for any help!