Not compatible with Firefox 28 Mac Rated 1 out of 5 stars

Alleged to work with Firefox 24 and up, but not compatible with Firefox 28 Mac — no toolbar button, therefore not usable at all. Like quite a few Firefox add-on developers these days, this gent has not bothered to test his brainchild properly.

hola. Rated 2 out of 5 stars

trabaja pesimamente mal. no se acopla. inestable. es terco en sus controles y cambios de ajuste. no acepta los cambios que uno le aplica.

This review is for a previous version of the add-on (4.9). 

Rated 2 out of 5 stars

Although I absolutely love the idea I did not found any theme I liked too much and the default ones can screw with functionality on some websites.

This review is for a previous version of the add-on (4.9). 

You are encouraged to compose your own default theme using the basic HSLA transformations.

UPDATE
> The user informed me that he would like to impose certain text or background colors on input elements.

'Color Transform' and 'Colorific' cannot target elements of a specific type. Your best bet is to add specific CSS rules using e.g. 'Stylish', 'User Style Manager' or 'Color That Site'. Given that input elements normally don't contain background or foreground images, it should be possible to obtain a readable result.

> The user informed me that the lack of contrast in most themes led to e.g. indiscernible rating stars.

Color Transform and Colorific are not meant for contrast enhancement, but mainly for darkening pages in order to reduce eye strain in dark environments. However, Colorific's single-spectrum themes retain quite a lot of contrast, while e.g. a mere brightness inversion in Color Transform retains all contrast.

The deeper reasons for the reduced contrast in most themes of Color Transform and Colorific are the following:
Background colors cannot simply be set because they need to be matched to background images. Images require non-constant transformations in order to retain contrast. These transformations are always narrowing down the range of colors if they are to have a similar effect on both bright and dark pages. It is not possible to determine whether a page is predominantly bright or dark without rendering it, and even after that it is hard to estimate. In addition, it is impossible to determine whether text is shown on top of one or more elements which have a CSS background image. Hence it is safe to set text and background colors directly to values with high contrast only if one also hides all CSS background images. In most cases this is unacceptable, because these images have many uses on modern pages as icons and other art work.

Rated 3 out of 5 stars

Doesn't work globally plus it comes to me as complicated with so many settings. Some might like them, I'm more in for something simple and working for all pages at once instead of manually having to set it up for every single page.

This review is for a previous version of the add-on (4.9). 

Rated 5 out of 5 stars

This is the best working add-on in that category.
There are cases where I would like to have some hue variations within a page, though. For example this review page, setting the stars in the rating did not show. What annoys me the most is that visited and unvisited links look exactly the same, if there is a solution for that I'd be glad to hear it.

This review is for a previous version of the add-on (4.9). 

The main reason for the limited contrast in the themes of Color Transform is that this ensures that more or less the same result is achieved on dark and bright pages. Simple transformations such as brightness inversion will retain most contrast, but these do not give you control of the resultant colors (for example, dark pages will become bright).

One of the underlying problems is that almost all modern pages use css 'background-image' styles both for backgrounds behind text and for foreground icons/images (such as stars). A theme may now either limit the background colors to a certain range or it may retain the contrast in background images, but it cannot do both.

However, my add-on Colorific contains several single-spectrum transformations that yield higher contrast but less control of the background color. Also, Colorific gives you freely designable themes, so you may try to find a better solution yourself.

For distinguishable link colors, the best solution is to increase the initial contrast in those colors in the Firefox content options.

Rated 5 out of 5 stars

Nice extension! Simple and work well

This review is for a previous version of the add-on (4.9). 

Just what I wanted Rated 5 out of 5 stars

Great ! I hate BLACK pages. Is there a way to save my preference for a domain? Thanks for this extension

This review is for a previous version of the add-on (4.9). 

Great potential, but I would like some additional features. Rated 4 out of 5 stars

All-in-all, I love this addon. For a long time I used Stylish for global page adjustments, but the problem with using a global style sheet setup like that is that not all web pages react the same way. It seems that Color Transform, however, reads the individual page data, including the page's own css, and tweaks it to adjust elements to conform to the color transformations set up in the saved color profile. As a result, it doesn't seem to matter how simple, or messy and complex, a page is, Color Transform can do the job and make the page conform to your desired scheme.

But some limitations to the addon make it so that I cannot quite rate this a 5-star addon...

Firstly, while you can choose one of the built-in color schemes, and modify it to customize it the way you want, you cannot save multiple custom color schemes, you can only save a single one. If you change the scheme and save the new customization, the old one is lost.

Secondly, I really wish that the adjustment increments were more fine-tuned. Even using the fine-tune small-increment settings, changing the Hue, Saturation, or Lightness of the color scheme makes some fairly significant and distinct adjustments. On the one hand, it is important to be able to tell the difference between one adjustment and the next, but on the other hand, I personally can distinguish very fine changes in such values, and would like more precise control. Perhaps in the future the developer can add in a third level of adjustment precision for ultra-fine adjustments?

And lastly, I personally would really like to see a built-in site exclusion list. While it is perfectly possible to turn off the change for a given website by turning off the transformations altogether, I would prefer to have it on almost all of the time, and to simply exclude specific rare sites.

I'd also like to make a feature request (other than hopefully seeing the above issues addressed)... I would love to be able to set a "daytime" color scheme, and a "night time" color scheme, and have the addon automatically switch between them (as an option) based on local system time, with the ability to set what times the addon makes that change. I have no doubt that would require a fair bit of additional coding, but I would love to see that option.

Oh, and I'd like to note that it doesn't seem to work with gmail.

This review is for a previous version of the add-on (4.9). 

Color Transform in its current form won't function in multi-process Firefox which is to be released in several months. I may choose to drop support for Color Transform in favor of Colorific. If you are capable of building a crowd-funding website for new Firefox add-ons / features, please do so.