Final answer:
Colors are perceptions of light wavelengths and do not have chemical compositions, but the pigments causing those colors can be mixtures or pure substances. Purple and orange are mixtures made from two different colors, while white and black could be complex mixtures or pure substances depending on their pigments. None of the options A to D are entirely correct as all colors mentioned could be considered mixtures.
Step-by-step explanation:
When discussing colors in terms of substances, it's important to understand that color itself isn't a physical substance but a perception created by the way our eyes interpret different wavelengths of light. However, the pigments or dyes that cause these colors can be considered as mixtures or pure substances in a chemical context. A pure substance has a constant composition and constant properties throughout the sample. This can be either an element, which is made up of one type of atom, or a compound, consisting of more than one type of atom bonded together. On the other hand, a mixture is a physical combination of two or more substances, which can be separated into their original components. Mixtures can be either homogeneous (uniform composition) or heterogeneous (non-uniform composition).
For instance, purple is typically created by mixing red and blue, so it is a mixture. Similarly, orange is made by mixing red and yellow and is also a mixture. The colors white and black can be a bit more complex. White light is a mixture of all the different colors of visible light, and although a white pigment might be a single compound, it commonly scatters all wavelengths of light, performing like a mixture of colors. Black pigment absorbs most of the light that hits it, and it could be either a single substance or a mixture of pigments absorbing light at various wavelengths.
None of the options A to D are correct because all the mentioned 'colors' in the context of pigments or dyes could be considered mixtures depending on their composition. In general, most colors we use in dyes, paints, and printing are mixtures rather than pure substances.