Multi-color photometry is presented for a sample of 60 dwarf ellipticals ( dE ) selected by morphology .
The sample uses data from GALEX , SDSS and WISE to investigate the colors in filters NUV , ugri and W 1 ( 3.4 \mu m ) .
We confirm the blueward shift in the color-magnitude relation for dwarf ellipticals , compared to CMR for bright ellipticals , as seen in previous studies .
However , we find the deviation in color across the UV to near-IR for dE ’ s is a strong signal of a younger age for dwarf ellipticals , one that indicates decreasing mean age with lower stellar mass .
Lower mass dE ’ s are found to have mean ages of 4 Gyrs and mean [ Fe/H ] values of - 1.2 .
Age and metallicity increase to the most massive dE ’ s with mean ages similar to normal ellipticals ( 12 Gyrs ) and their lowest metallicities ( [ Fe/H ] = - 0.3 ) .
Deduced initial star formation rates for dE ’ s , combined with their current metallicities and central stellar densities , suggests a connection between field LSB dwarfs and cluster dE ’ s , where the cluster environment halts star formation for dE ’ s triggering a separate evolutionary path .