\begin{table}%t2
%\centering
\par
\caption{Color correction factors to be taken into account in order to
transform the PRONAOS flux intensities from a ($T=30$~K, $\beta=2$) 
spectrum to a ($T$, $\beta$) or Rayleigh-Jeans (RJ) spectrum.}
\label{tab_correction_colour}
\begin{tabular}{cccccc}
\hline
\hline
$T$  [K] & $\beta$ & \multicolumn{4}{c}{$\lambda_{\rm ref}$ [$\mu$m]}\\
   &         & 200 & 260 & 360 & 580 \\
\hline
30 & 2 &1.00&1.00&1.00&1.00\\
20 & 2 &0.98&1.00&1.00&1.02\\
10 & 2 &0.80&0.92&0.97&1.05\\
50 & 2 &1.00&1.00&1.00&0.98\\
30 & 1 &0.97&0.99&0.99&1.02\\
30 & 3 &1.01&1.00&0.99&0.94\\
RJ &   &0.98&0.98&0.97&1.01\\
\hline
\end{tabular} 
\end{table}