You are correct! Dry sodium chloride (NaCl) and solutions of nitrates containing sodium (like sodium nitrate, NaNO₃) all impart the same bright yellow color to a flame. This is because the color is not due to the anion (chloride or nitrate), but rather the sodium cation.

Here's why:

* Excitation and Emission: When you heat sodium salts in a flame, the energy from the heat excites the sodium atoms. This means the electrons in the sodium atoms jump to higher energy levels.

* Energy Release: When these excited electrons return to their ground state (lower energy level), they release energy in the form of light.

* Wavelength and Color: The energy released by sodium atoms corresponds to a specific wavelength of light, which falls in the yellow part of the visible spectrum.

Therefore, the yellow color is characteristic of sodium ions (Na⁺) and not specific to the anion present in the compound.

This is a very useful phenomenon in chemistry. Flame tests are used to identify the presence of certain elements in a sample based on the color they produce when heated in a flame.