A new approach of generating high-repetition-rate picosecond pulses at sequentially switching wavelengths has been proposed and experimentally demonstrated. The approach is based on subharmonic pulse-gating and self-seeding of a single Fabry-Perot laser diode. Output of up to ten wavelengths at a repetition rate of 10 GHz has been achieved. The output exhibits a relatively uniform power across the selected wavelengths. The nonlasing modes are being suppressed by more than 20 dB. The maximum timing jitter of an individual wavelength and the ten-wavelength output are measured to be 222 and 181 fs, respectively.