I've been working on the next update to Acorn, version 5.5, and I've got a build ready for folks to try out. I'm calling it beta 2. Hello, it's nice to meat you.
Color improvements are the focus Acorn 5.5. The biggest change is a new color loupe tool for Acorn which will allow you to seamlessly select colors from the canvas as well as anywhere on your display (and correctly match your display's color to the selected color profile of your image).
This is super important as displays with a wider-than-sRGB-gammut (such as the recent iMacs) are starting to show up on our desktops. For instance, if you have an iMac with the Display P3 profile set and you're working on an sRGB image, selecting a color from anywhere on your display will correctly match it to your image. Colors are hard, but Acorn is making it so you don't even have to think about it.
You can bring up the color loupe tool by pressing the option key when using Acorn's various drawing tools, or by pressing Control-C when you have an image open.
And besides supporting wide color gamuts, Acorn 5 has always supported deep images (16 bits per component), which is going to be increasingly important this fall when Sierra ships with deep color support in AppKit, and if you're paying attention to the tea leaves for iOS…
New dither filters, shape processor improvements, and various Quality of Life things are in Acorn 5.5b2 as well.