Colorify

The computer reads any webpage and decorate it with colors, highlighting the grammatical structure. By making it easier to scan the page with your eyes, it trains your brain on a subconscious level and improves your reading comprehension.

You can set custom colors in the extension options.

You can also enable deep learning mode in the options to have slower but better parsing quality. Be aware that deep-learning mode may use the graphics card which may cause your computer to reboot if it encounters video driver issues.
With this deep learning mode you can also display the sentence dependency tree.

The root is underlined in black. The width of the orange underlines denotes the depth inside the dependency tree.

English only for the fast parser. English and French for the deep-learning mode starting from version 0.96.

Version 0.98 is smaller and faster but less accurate.