Three-dimensional colloidal photonic crystals containing a fluorophore, and fabricated by inward growing self-assembly method, are infiltrated with gold nanoparticles of 5-nm diameter. The effects of localized surface plasmon resonance of gold nanoparticles on the stopband of the photonic crystal are investigated by tuning the reflection band to overlap with the plasmonic band. Interestingly, reflection spectra of gold-infiltrated PhC show a clear suppression in the reflection band around the stopband center at higher angles of incidence due to the efficient coupling between the plasmon and photon modes inside the crystal. The resonant absorption appears only when there is a significant overlap between the stopband and the plasmonic resonance. The role of plasmonic resonance towards the enhancement of emission at the band edges is also discussed from the experimental results on the dielectric and metallo-dielectric photonic crystals.