Color with alpha Jul 11, 2015

Hi everyone! This week I wasn’t able to work on Aseprite as much as I’d wish (as result of some personal issues). Anyway as there is a big change coming for the next release I think that some feedback from you will be a great help. (Make your comments below.)

Next version will contain better handling of Alpha component (issue 286). It means that palette entries, foreground color, and background color will have an Alpha component:

Color with alpha

The idea is that you can replace RGBA values from each pixel in an easy way. You pick a pixel (RGBA values) and then you replace pixels (RGBA values). This is pixel-art friendlier, but requires some important User Interface changes.

Default Ink

On current Aseprite versions the “Default Ink” composites the paint color with the layer color depending on the “Opacity” level. Now we would prefer a “Replace Pixel” ink by default. In this way when you paint, all four components (RGBA) are replaced:

Replace pixel ink

The new default ink (“Replace Pixel”) doesn’t use “Opacity”, so the Context Bar will not need the “Opacity” slider by default (It’s replaced by the Alpha component in the current color). It makes a cleaner initial interface.

The “Opacity” slider will be used to control the intensity of the tool change, and will be available only for:

  • “Alpha Compositing” ink (merge paint RGBA + layer RGBA), or
  • “Lock Alpha” ink (merge RGB + layer RGB, doesn’t modify Alpha), or
  • Effect tools (like Blur or Jumble).


Eyedropper will contain more options to grab different components:


The default “Color+Alpha” option will pick RGB+Alpha, Gray+Alpha or just the palette index depending on the sprite color mode (RGB, Grayscale, or Indexed). But now you will be able to choose other options. E.g. pick RGB values without modifying the current Alpha, or pick just the Alpha component so RGB values stay the same, etc.

Generating RGBA palettes

We will be able to generate color palettes with Alpha components:

Generating palette

These kind of palettes can be saved on 8-bit indexed PNG images, which support the alpha component on palette entries.