PUBLIC MARKS with tags html5 & color

but some of the parts of the image are specifically #ff0000 and I would like to be able to replace it by some other color, a custom user defined color.

A couple of months ago, we posted a blog post on bringing blending to the web. Since then, Nikos Andronikos from Canon and I have been busy integrating feedback in the draft spec and we presented it to the CSS working group in May. At Google I/O Vincent Hardy also gave an overview of the capabilities. If you’re interested, you can watch it here. (The part on blending and compositing starts around 55min.) The WebKit build he is using is also publicly available so you can experiment with these features.

Demo showing CSS Filter Effects 1.0, specifically the filter functions, which are being implemented in Webkit.