Didn’t find anything regarding this subject after looking around for a bit.
It would be nice if it’s possible to add a function for the marquee tool that allows user to invert the selection with the marquee tool, i.e. “deselect everything except all selections within this selection” (ergo, not “invert selection”).
Right now, Aseprite have the following options for its selection tools:
I think you are requesting for “Intersect with selection”, which I totally agree, In fact I was about to suggesting it myself 
@dacap I’ve made a gif to show the “intersect” behaviour compared to the other 3 ones in case it could be useful.
Yes! Thanks, don’t really know why I didn’t know what it’s called. Would be really useful nonetheless!
No problem, I didn’t know what is called either, I had to look it in Photoshop XD
Could you please change the topic title to avoid misleading the devs? I hope they also like the idea
Actually the intersection mode is available in the code, but there is no UI to access it. I remember a related issue:
Basically the requested feature is the intersection mode for Select > Color Range too.
Please, I need this. I find very useful for backgrounds and sometimes I have to use other software.
That sounds like good news! 
Is there any possibility to see it implemented in a upcoming release?
Also, I’d like to suggest a change in the default shortcuts (to use the more “standarized” ones):
Maybe 
I’m not sure about that shortcut. Some years ago, when the Alt key stopped working to use the eyedropper (e.g. to change background color) that was bad news for some users. So the Alt modifier should be kept for the eyedropper even when we are using the selection.
Oh, I see, I suppose there are also people who want the eyedropper to show with non-drawing tools, like the selection ones (I don’t agree with those users tho XD).
I have then a suggestion (a bit complicated I fear), so we all could be happy and enjoy our preferred shortcuts
Maybe you could make an option under “Preferences > Selection” (for example) that could let us choose that behaviour?
Sorry about insisting, but I would really need this, because I use selection shorcuts a lot, and my brain aches each time I change between Aseprite and Photoshop XD
Actually this is already possible adding the Alt shortcut for some of the actions in the Selection context:
In this way we override the Alt for the eyedropper when we are selecting.
I had no idea! I have just tried and it worked flawlessly! Thank you very much!!
For the next version:
Thats great news! Thanks alot!
Thank you so much @dacap! You are the best!
