Blender doesn't have the same red to green type of colour gradient indictating range of influence like 3dsMax does for instance. What you can do with Blender though is refine your proportional edit immediately after the function is executed. For example if you perform a proportional edit, as soon as you release your finger from the mouse you will see on the bottom left of your screen a range of variables appear (under the toolshelf panel) . Here you can change influences such as falloff amount and falloff profile by either using the slider or typing in a numerical amount. Also if you press F6 the same range of variables will appear as a floating window.

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