How long can spark plugs last? There are two types of spark plugs: conventional and long-life (platinum- or iridium-tipped). Conventional spark plugs need to be replaced every 30,000-50,000 miles. Recommended replacement intervals for iridium- or platinum-tipped spark plugs vary between 50,000 and 120,000 miles. To find out the recommended replacement interval for your car, check your maintenance schedule.
Its key principles: (1) the three primary colors are red, yellow and blue, (2) the primaries exist as three material substances (often identified with specific pigments), (3) the primaries cannot be mixed from other colors, but can mix all other colors.
These colors are pure -- you can't create them from other colors, and all other colors are created from them. Secondary colors are orange, green, and violet. They line up between the primaries on the color wheel because they are formed when equal parts of two primary colors are combined. Tertiary colors are formed by mixing a primary color with a secondary color next to it on the color wheel.