How do I change the color of a Venetian plaster wall?

This sounds like a good approach:

http://community.homedepot.com/howto/DiscussionDetail/Painting-OVER-venetian-plaster-906500000000FJE

Hi Jeff, OMG!!! I just removed all of the Venetian plaster in my daughters room right after Christmas. Wow, was that something else! This is my next post on my blog so you might want to stay tuned. But it sounds like you like the Venetian plaster but just want to change the color? How do you know it has a wax? Did you do all the Venetian plaster but didn't like the color? or was that there before? The reason I ask is because if it has been there a while, maybe it is sealed with something and not wax. Wax usually will wear over time. I would lightly sand them again if you can. If you try to remove it with a stripper or mineral spirits, you might have a mess on your hands with it removing the baby blue and other layers. Get a drywall sander and lightly sand the walls down. Now, that will give you a nice base to apply the other color while keeping the Venetian plaster intact if you like it.

I wanted smooth walls again ...like a new room. I couldn't stand the bumpy Venetian plaster walls that were just trying to mask an old dingy room that had 5 coats of paint on the molding . Plus it was 80's Venetian plaster. The color was mixed with a plaster, so sanding by hand was not going to make it smooth. To remove it completely we rented a drywall sander that comes with an electric sanding disk with vacuum hookup. It was awesome! We had a process of sanding and spackling we did to turn the walls completely smooth. With new molding, the room looks completely like new construction. This is my next blog post if this is something you are wondering:). Good luck!

You might try a water based wax remover. I've seen it before but it might be an international vendor.

Here is an idea for your project

https://www.hunker.com/13417037/how-to-paint-over-waxed-venetian-plaster

Never heard of waxed Venetian plaster. Ammonia removes wax.

Yup. Mineral spirits will remove the wax. Apply it to a clean cloth and try a small spot first. Also you can use one cup of lemon scented ammonia to one gallon warm water. Try a small spot also. Don't saturate the wall with this.

Just to clarify for Kelli. The wall is Venetian plaster that has a polished wax finish for protection and higher buffed gloss

Thanks to all the response. For K Rupp, the walls are very smooth and look like marble. I did it a couple of years ago. Started with a normal orange peel drywall. First I had to get more drywall mud and go over all the orange peel to make it smooth and then sand. Once that is done seal with a water primer and then paint a base coat in your desired hue. Then apply three coats of Venetian plaster very thinly and randomly letiing the under coats show through. Then you burnish with a stainless spackle blade to burnish. When you are happy the final step is to apply a coat of clear wax and buff to a desired sheen.

I should have listened to my sister and gone with the grey originally, because everyone knows girls are smarter than boys;)

now I just want to change the blue unnatural marble look to a naturals grey one

You should be able to paint over it like normal. Make sure to wash down the walls and prime first.

I am doing a Venetian embossed pattern. I had mica powder on wax, multiple passes with like minded colors. I HATED IT! Lmao. So thank you for the ammonia suggestion. I started slow and found the embossed burnished pattern. Coloring muted. Much better!!

Thanks for this to the person that posted ammonia+water!