Narrow band photometry is presented on 27 dwarf ellipticals in the Fornax cluster .
Calibrated with Galactic globular cluster data and spectrophotometric population models , the colors indicated that dwarf ellipticals have a mean [ Fe/H ] of -1.00 \pm 0.28 ranging from - 1.6 to - 0.4 .
The mean age of dwarf ellipticals , also determined photometrically , is estimated at 10 \pm 1 Gyrs compared to 13 Gyrs for bright Fornax ellipticals .
Comparison of our metallicity color and Mg _ { 2 } indices demonstrates that the [ Mg/Fe ] ratio is lower in dwarf ellipticals than their more massive cousins , which is consistent with a longer duration of initial star formation to explain their younger ages .
There is a increase in dwarf metallicity with distance from the Fornax cluster center where core galaxies are , on average , 0.5 dex more metal-poor than halo dwarfs .
In addition , we find the halo dwarfs are younger in mean age compared to core dwarfs .
One possible explanation is that the intracluster medium ram pressure strips the gas from dwarf ellipticals halting star formation ( old age ) and stopping enrichment ( low metallicity ) as they enter the core .