Dweste,

The idea of measuring color by wavelength (angstrom,nanometer) or by frequencty, or by temperature, only applies if the color you are trying to render is a singular component, or pure color. Most of the colors in nature are a blend of two other colors, or frequencies, such as any brown color is a mix of two or more colors at fairly opposite ends of the spectrum (red and green make a base brown). Then there is the question of intensity, which further complicates the issue. You can render any color variation using the primary colors (red, blue, and yellow)in combinations and instensities, except for flourescent colors, which involve another spectral issue altogether.

Color charts are the best way to go. For that, I would suggest an interior design/paint department.

Good luck.