4 x 64 GIF (from ulillillia via rising tensions) stretched to 450 x 400 and smoothed by...your browser!
Accepting data added to your images against your will by herd-following programmers and designers, or how I learned to stop worrying and love the anti-aliasing of everything.
The image above will be seen as "normal" on the SeaMonkey browser or Internet Explorer 6. In other words, by very few. It might surprise you to know the purple smear in the middle of this GIF is a clean line dividing red and blue. But it doesn't matter. Must...stop...caring.