Want to emulsion lime green wall with a peach matt emulsion. Would it need a white emulsion first, to 'kill' the green colour?
Also, the peach emulsion is going to be mixed specially/colour matched at B&Q. Is there such a thing as a washable matt, when using this colour-mixing technique, just so that I know in advance.
Things like dirty handprints and everyday spills can be wiped from any emulsion paint.
While it will most likely take two coats of the peach, it certainly wouldn't hurt to 'white' the lime green first. Though not totally necessary.
I would always blank out with white, just because it's probably going to take two coats of peach anyway, and if you don't you may also need a third. Saved money white's a lot cheaper than colour mi xed.
Muskox, if you do decide to apply a mist coat and are planning to use cheap emulsion for this purpose, i doubt whether you would need to add much water. Usually 10% to 15% of water is added to the paint for a mist coast. However, it is my experience that the very cheap emulsions are quite 'liquid' in nature and need very little water - if any- to thin the paint enough for a mist coat.