Modify Tiles on QML Map with OSM plugin.

[trcrenshaw]

Is it possible to modify Tiles before they are displayed on a Map with the Open Street Map Plugin?

We have a simple tile server setup with some grayscale tiles where each pixel represents some data (humidity, temp elevation etc.) at the given point. We'd like the user to be able to select the color scale they would like for the tiles, so we were hoping to find a way to be able to modify the tile image once its downloaded from the server. Is this possible?

Or should we try to download the tiles from the server to a local directory and modify them, and point the Map Plugin to the local directory instead?

I'm open to any other suggestions as well.