Hi owen. It is a good suggestion, that would be a cool feature for the drawing tool. There are some workarounds or methods for this, but not as flexible as your idea would be, in some ways. One existing quick feature is TINT on an individual graphic. If you have a room in your castle and the Floor or the Room is a single graphic, GM can open it as a token or drawing and add a red tint, the tint appears like a certain reduced opacity. This method does not work as well as your shape-tool idea because Tint can only affect a whole graphic, not a particular section. On the upside, if you need to "grimdark" your entire bright castle map, try putting a black tint on the entire background map. Tint settings in wiki docs, <a href="https://wiki.roll20.net/Token_Features#Token_Setti" rel="nofollow">https://wiki.roll20.net/Token_Features#Token_Setti</a>... Alternately, the opacity effect can be achieved with PNG graphics overlaying, or certain Marketplace graphics. In this method you make a red circle or square PNG with opacity, and then drag-drop-stretch it over the areas that you want to colorize on tabletop. This same idea has been used to create the appearance of rain, clouds, treetops, or spell effects. The tricky part of this method is z-order or layering, because it's harder to select Tokens if they go under a large PNG overlay. One option is to send it "To Back" or to Map Layer and thus only colorizing the map but not the Characters tokens. Examples of color overlays in the Marketplace (Note: You can also make your own generic red square/circle and upload it): Environmental Effects 1 (Rain, radiation, fog), <a href="https://marketplace.roll20.net/browse/set/539/envi" rel="nofollow">https://marketplace.roll20.net/browse/set/539/envi</a>... Environmental Effects 2 (sandstorm etc) <a href="https://marketplace.roll20.net/browse/set/643/envi" rel="nofollow">https://marketplace.roll20.net/browse/set/643/envi</a>... Blue red and green Cloud overlays from this, <a href="https://marketplace.roll20.net/browse/set/565/fant" rel="nofollow">https://marketplace.roll20.net/browse/set/565/fant</a>... Trees, <a href="https://marketplace.roll20.net/browse/set/583/alie" rel="nofollow">https://marketplace.roll20.net/browse/set/583/alie</a>... Frost clouds, magic clouds, gas cloud, <a href="https://marketplace.roll20.net/browse/set/822/terr" rel="nofollow">https://marketplace.roll20.net/browse/set/822/terr</a>... Spells, poison cloud, <a href="https://marketplace.roll20.net/browse/set/301/chao" rel="nofollow">https://marketplace.roll20.net/browse/set/301/chao</a>... Spells, lightning, <a href="https://marketplace.roll20.net/browse/set/283/magi" rel="nofollow">https://marketplace.roll20.net/browse/set/283/magi</a>... Hope this helps you achieve the lighting that you want in the meantime.