Creating A Color Map UI

I’m trying to create an interface that looks like the image below. Where “hot” areas would be set to a specific color and then have a gradient color outward until it reached the other specified color. There would be multiple “hot” areas in the interface, which would cause intersecting gradients. I thought that using a decorationBox with a RadialGradient would work, but this limits me from creating multiple “hot” areas that would have intersecting gradients. I am new to flutter and not even sure what design options are out there for creating something like this. Any ideas or direction of where to being looking would be appreciated!