This section talks about how Aseprite manages color.
Along with this, there are two active colors that can be used to paint or erase parts of the sprite:
You should learn more about them in the Color Mode section.
The color profile indicates in which color space are meant to live RGB values of the image. It is used to match RGB values in one device (e.g. your monitor, where you create your image) with other device (e.g. the user that will watch your image in her/his monitor). Images on Internet generally use the sRGB color space.
Learn more about this in the Color Profile section.