The reasoning here is simple. Every color in the visible spectrum can be assigned a number based on a luminosity scale (a scale from light to dark) from 0 to 9 where white is 0 and black is 9. Now suppose that the brown you are trying to cover has a score of 8, and the yellow paint you want to apply has a 4. Store your leftover paint in plastic Rubbermaid beverage jugs or other plastic seal-able containers. Paint left in the can always gets funny after time. Either the can isn't properly sealed of it gets exposed to extreme heat or cold. I like to store my paint inside where the temperature is controlled. Limewash - Made from slaked lime and water, this paint is good for porous surfaces such as brickwork, render and plaster and gives a chalky finish. It is available from specialist companies.
Materials and their application, every paint manufacturers paint will vary. If you are freshening up old walls and painting back to the existing color, the product doesn't have to be high end or have good coverage. If you need to paint a dark color over light color or light color over dark, you may want to consider purchasing a top quality paint to avoid multiple coats. I suggest Valspar, Pittsburgh or Benjamin Moore top of the line wall paint. These brands work well for straight out of the bucket use and are application friendly. Sherwin Williams is not my first choice because the coverage is poor and you will have to apply multiple coats but, it does apply, fluently. If you find a product does not apply well, maybe it is to heavy and/or sagging on the wall, you may need to thin the paint with a little water, this will reduce the coverage but make the paint flow better and lay down nicer on the surface. I do recommend latex paints for all applications, these days a good high end latex is as good as oil paint and your tools clean up much easier, it will also be less harsh on the respiratory system. The only situation I recommend oil paint, is as a primer/stain blocker over stains that "bleed" through the paint. You can get a stain blocking oil primer in a convenient spray can and spot prime any trouble areas before painting and in the case you need to prime all of the wall due to smoke or water damage, I recommend getting it in gallons and rolling it on where the stains are present. Don't forget proper ventilation and/or a respirator when using the oil based primers! Have plenty of newspaper around. After you clean your brushes wrap them in a plastic bag. Specialist paints also include some exciting new finishes, such as suede effects, metallics and high-sheen lacquers. Judy Smith, colour consultant at Crown, suggests an accent wall in one of these to lift a neutral scheme. Crown's Feature Wall range, which includes eight metallic finishes, nine bright colours and a highly reflective Pure Brilliant White, comes in convenient 1.25 litre tins. PRIMARY COLORS. The primary colors are red, yellow and blue. These colors are your base colors from which all other colors come from.