We investigated hybrid zero-dimensional core-shell CdSe/ZnS quantum dot (QD)/two-dimensional monolayer WSe2 semiconductors with an Ag nanodisk (ND) for manipulating plasmonic-enhanced photoluminescence (PL) and color conversion efficiency. The absorption spectrum of the local surface plasmon resonance (LSPR) effectively overlaps with that of QDs or monolayer WSe2 to considerably enhance PL. The broad absorption spectrum of the LSPR simultaneously overlapped with the emission spectrum of QDs and the absorption spectrum of excitons in WSe2 to enhance the color conversion efficiency. The highest efficiency of color conversion from QDs to WSe2 with Ag ND was 53%. In the future, hybrid QD/transition metal dichalcogenide light emitters could be further integrated with GaN-based white light-emitting diodes to manipulate the color temperature and expand the color gamut to develop a miniature white light-emitting diode.