We present integrated JHK _ { s } 2MASS photometry and a compilation of integrated-light optical photoelectric measurements for 84 star clusters in the Magellanic Clouds .
These clusters range in age from \approx 200 Myr to > 10 Gyr , and have [ Fe/H ] values from -2.2 to -0.1 dex .
We find a spread in the intrinsic colours of clusters with similar ages and metallicities , at least some of which is due to stochastic fluctuations in the number of bright stars residing in low-mass clusters .
We use 54 clusters with the most reliable age and metallicity estimates as test particles to evaluate the performance of four widely used SSP models in the optical/NIR colour-colour space .
All models reproduce the reddening-corrected colours of the old ( \geq 10 Gyr ) globular clusters quite well , but model performance varies at younger ages .
In order to account for the effects of stochastic fluctuations in individual clusters , we provide composite B - V , B - J , V - J , V - K _ { s } and J - K _ { s } colours for Magellanic Cloud clusters in several different age intervals .
The accumulated mass for most composite clusters are higher than that needed to keep luminosity variations due to stochastic fluctuations below the 10 % level .
The colours of the composite clusters are clearly distinct in optical-NIR colour-colour space for the following intervals of age : > 10 Gyr , 2 - 9 Gyr , 1 - 2 Gyr , and 200 Myr -1 Gyr .
This suggests that a combination of optical plus NIR colours can be used to differentiate clusters of different age and metallicity .