Here is a simple Amibroker tutorial to build a good looking trading system. Just have a look into the charts provided below where the buy signals are represented by Red and Black blended gradients and the sell signals are represented by Pale Green and Black blended colour gradients.
If you want to seperate your charts into Zones (For example Bull Zone or Bear Zone) then the functions colorBlend and the parameter styleGradient comes handly. Here is a below example which can be mapped with any trading system. Just copy the codes and paste to your trading system afl below the Buy/Sell parameters. And you are done.