For the negolyte, both the RMSE of concentration (Fig. ) and SoC (Fig. ) remain low when using the genetically optimized wavelength positions (black lines), regardless of the number of wavelengths selected. This is expected since the negolyte exhibits a linear spectral response, allowing low RMSE values to be achieved with just two strategically chosen wavelengths-specifically those with high absorbance variation (see Fig. )-as when using the full spectrum . The algorithm finds two optimal regions for wavelength placement: at high wavelengths (>850 nm), where V III does not absorb and the absorbance is dominated by V II ; and around 600 nm, near the global maximum of the spectrum, with its exact position varying based on the SoC. As the number of wavelengths increases, they concentrate within these two regions, where the spectral variation is more pronounced, and to a lesser extend around 690 nm, where V II shows a local minimum. In contrast, channels placed at equidistant positions (blue lines) result in higher RMSE values as some of them may fall in regions of minimal spectral change.