I use and recommend the Tint method as well, like Franky said. It's not obvious at first but graphics/objects on the Map layer can take a Tint on their token settings tab! Wiki docs for this, <a href="https://wiki.roll20.net/Token_Features#Tint_Color_" rel="nofollow">https://wiki.roll20.net/Token_Features#Tint_Color_</a>... Alternately, if you get into the semi-transparent overlay method as-in Jebediah's latest post, with that method you can also do effects like rain, fog, sandstorm, snow. Environmental Effects 1 overlay pack from Marketplace, <a href="https://marketplace.roll20.net/browse/set/539/envi" rel="nofollow">https://marketplace.roll20.net/browse/set/539/envi</a>.. You probably could combine the methods, adding different tints to your semi-transparent overlay, if you want to take that approach.