Rated 1 out of 5 stars
This is an amazing add-on, but I am rating it 1 out of 5 stars because: it doesn't automatically apply the changes before displaying the webpage making it completely unusable at night (versus the way Stylish forces changes before load, thus stopping websites from flashing white before the color is changed), it really needs a blacklist when a global color scheme is set (I don't want it to show on cert error pages) and it makes page hang while loading a new page more noticeable because it takes longer to load pages. Perhaps you (developer) could make Color Transform save changes to Stylish?This review is for a previous version of the add-on (4.2).
The flashing of new tabs could be remedied by changing the browser element background color, which I have added to the desired features list (please donate to make it likely to happen :). Colorific, one of my other add-ons, has an option to delay the first paint of web content, which usually suffices to prevent flashing of loading web pages (but you might not like that solution). It also has an option to apply color transforms to white-listed domain only (it has no black-list).
As for Stylish: Color Transform and Colorific work with custom transforms, not CSS transforms. This makes it possible to use arbitrary algorithms for color transformation, but makes it impossible to generate user style sheets. I will consider changing my implementation when the new CSS color spec with HSL filters is implemented in Firefox.