[R] plot data with a colour scale - more details!

[Ahmed, Rayhan]

Hello again,

I am trying to create a color scale plotting the hydroathy index (y-axis) versus residue (x-axis) -  each residue (1-100) has a value between 0-1. I've been trying to create a scale where:
0-0.499: increasing intensity of red
0.5- yellow
0.51 - 1 increasing intensity of green.

THis is in lieu of a line graph.

I'm not sure which type of plot to begin with - I attempted to modify a heat plot, but it did not work.

Any assistance would be greatly appreciated.

Thanks again, and sincerest apologies for the inconvenience.

-ray