I knew there was an add-on that came very close to inverting the colours like windows magnifier and linux' xcalib would do it. It took me some time to find it because it's not as popular as it deserves to be.
Sometimes inverting the colours for everything on the screen isn't what you need. This is when this kind of addons come in. They only invert what's inside the browser. I've tried other popular addons for this purpose but they either leave some ugly areas and lines uninverted or don't allow you to choose whether you want to invert images as well or not.
This addon fixes both problems. It can invert the webpage colours without leaving those noticeable uninverted parts and also allows you to decide what to do with images. Just what I need for night usage.
I can't comment on the other modes because I mostly use the invert feature (though I was able to get some amazing themes and visual effects by messing around), but I highly recommend this addon for any users of apps like windows magnifier looking for an alternative that only affects the web browser. Thanks so much to the author! this addon is absolutely dependable
Long story: I've done some intensive testing on all available add-ons in FF (and chrome). There are about 5-6 "night readers" on each. In general, the "inverters" in FF (unlike chrome) are all a bit worse in tems of not breaking the websites (i.e unusable for default browsing). So the only solution is to use a "themer", the best of which is this (Check Theme 10)! And if you need additional contrast, apply an inverter on top of it (It works (eg. Aniverto)! Or a web-site specific themer, It also works (eg. Black Google)! If you don't like this due to low contrast, your only other real option is to use "Screen Dimmer" but this is way better and in my experience it is the ONLY viable alternative in FF. Without it, I would have no option but to revert to chrome. So, thank you dev!
PS. If you can do the impossible and increase font brightness a bit or at least do some magic with the plague of "bright flashes on loading" (that plague both chrome and FF for ages!) that would be 5+ stars!! Ratings are based on eye-strain!!
Хорошо, что дополнение работает только в пределах текущей вкладки, а не всех, как это делает дополнение "Blank Your Monitor + Easy Reading". Однако, там есть настройка горячих клавиш, чего нет здесь. Весьма неинтуитивный интерфейс. Предпочел бы, чтобы стандартных вариантов 10-й и 16-й темы было больше. Upd. Версия 4.9.3 под указанный сабж перестала сохранять пользовательские цвета. А из предлагающихся нет нужной (темно-синий фон, светло-желтый текст).
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.
Thanks for reporting. You'll understand that not all developers have enough time and/or money to test on all combinations of platforms and applications. They would be helped with more user feedback. All I can see in the add-on statistics is that 7% of the current users is on a Mac and about 10% is using a Firefox version older than 29.
I have encountered other add-ons that caused issues with toolbar buttons in the past. Before Firefox 29 was released, every add-on had its own code to manage these buttons. A solution would be to install Firefox Developer Edition besides Firefox 28 and to use it to test or use add-ons that require (or work better) with newer versions of Firefox. This should be unproblematic because the Developer Edition has a separate user profile.
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.
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 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.
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.
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.
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.