and $I_G$ are the scattered blue and green intensities respectively, and the angled brackets denote ensemble averages.

In this arrangement, it can be shown [@two-colour] that only the singly-scattered light of each color probes exactly the same Fourier component of the density fluctuations and thus are correlated. All other, multiply-scattered, light does not probe the same component for both colors and is completely uncorrelated and thus does not contribute to the time-dependence of ${g^{(2)}}(q,\tau)$. This can be expressed [@two-colour] in terms of the normalized single scattering dynamic structure factor, $f(q,\tau)$: $$\label{eq:g2}
{g^{(2)}}(q,\tau)= 1 + \beta^2\beta_{MS}^2\left[f(q,\tau)\right]^2\;,$$ where the factor $\beta^2$ depends on the ratio of detector area and coherence area for single scattering and also on the overlap of the scattering volumes probed by each color. This factor is instrument related and dependent on scattering angle but not on the sample used. The other factor $\beta^2_{MS}$ reflects the fraction of singly-scattered intensities, $\left<I_B^S\right>$ and $\left<I_G^S\right>$, relative to the total (singly and multiply) scattered intensities: $$\beta_{MS}^2 = \frac{\left<I_B^S\right>\left<I_G^S\right>}
{\left<I_B\right>\left<I_G\right>}\;.$$ The concentration of polymer in our samples is low. The highest ratio of intensity scattered from polymer to that from colloid was measured to be $4\times10^{-3}$. This highest ratio only applied for one 