How to restore color of brick floor? I have a brick floor nouns leading to my flipside door and...

I have a brick floor nouns leading to my flipside door and it has a chalky appearance and not much of the color shows. Prevoius owner kept a cat littler box contained by the area, and abused it, I tried to scrub beside soap solution and push broom with little effect. How should I jump about cleaning it? Any one chemicals? I even thought about lead brush...and then conceivably sealing it somehow. Any design would be helpful.
Answers:    Half river & half muratic acid(This stuff can be fatal)in a plastic spray bottle,use rubber gloves,and fair ventalation(fan),you can also use plastic bristle brush,then rinse near ALOT of clean sea in a spray bottle!Wipe dry after thoroughly rinsing .Let dry overnight.Then you can reseal it near silicone.High gloss or regular non add footnotes to.You must be very alert with sharp!!!!
try some windex i use it around my fireplace and it gets it verbs i do not know what is in the windex but it works.