Photometric diagrams of the cluster ID27 (large white dot). Panel a) shows the WFC+ACS passband magnitudes (in red) of the cluster ID27 compared to all other clusters from the catalogue (in blue) vs. wavelength. Magnitudes and their uncertainties are indicated in the upper part of the panel. Panels b) and c) show the GALEX FUV-NUV colour vs. WFC3+ACS colours for clusters with available GALEX photometry from Kang et al. (2012). Panels (d)–s)) show colour-colour diagrams in WFC3+ACS passbands using the PHAT photometry. On y-axes (panels d), h), l), p)) and on x-axes (panels p), q), r), s)) colour combinations go from blue to red. In each colour–colour diagram 3 SSP (single stellar population) lines for solar ([ M / H ] = 0, red), intermediate ([ M / H ] = −1, cyan), and poor ([ M / H ] = −2, blue) metallicities are shown. Arrows indicate extinction vectors corresponding to A_V = 1. Error bars indicate observation errors of colours.