The authors present their study on high-order harmonic generation pumped by 400 nm wavelength laser from plasma plumes produced on the surfaces of various solid-state targets. The maximum harmonic cutoff was observed for Be plasma (31st harmonic, λ=12.9 nm). They compared these results with harmonic generation pumped by 800 nm wavelength laser. The authors demonstrated single harmonic enhancement for Cr, Sn, Sb, and Mn plasmas. They also studied the use of varying the chirp of the pump laser to control the enhancement of single harmonics within the plateau.