It would be awesome to customize map colouring based on user supplied rules. For example, I am often only interested in whether the temperature is less than say 0C, but the current colour gradients make it difficult to see the difference between -2C and +2C. I'd prefer to just colour areas that are forecasted to have below 0C temperatures. This could be easily extended to more complex user supplied rules, like

• temperature 1cm
• wind