All on 4 upper jaw has changed my face, the way I talk, and the colour of them is horrible. What do I do now?

Hi, I suspect you have already had this managed by an experienced implant dentist by now, since your time of asking your question. If not, rest assured that as long as the All-on-4 implants are suitably positioned, the teeth can be removed, modified/corrected or even changed and re-inserted without much difficulty at all in experienced hands. All the best, hope you achieve an outcome you are pleased with.

I would speak to your dentist to have a new set of temporary teeth made. the temporary teeth are prototypes for the final restorations. All problems should be worked out in the temporaries so there is no surprise in the final. The look, feel, bite, support of the face can be worked out.

It is still somewhat reversible so no need to worry too much, it can be corrected

It would be important to understand if the teeth you are talking about are the temporary set of the All on 4, or the final restoration, which is usually done 6 months after the surgery. It's impossible to diagnose and advise you without seeing you, but general issues that come to mind are the position of the teeth (not necessarily the implants themselves) relative to the jaw, and whether sufficient bone was reduced at the time of the surgery to make room for the transition line as well as the framework and infrastructure. These are just some of the questions that I would ask your dentists. I hope this helps. 

The nature of the All-On-4 treatment is such that the teeth component can be detached and adjusted or even completely remade. However, if the implant posts have not been correctly positioned in the first place, this may be somewhat more complicated to fix, but not impossible in experienced hands.