  We study the contrast for electrical and optical readout of NV centers in
diamond in dependence of the optical excitation wavelength using different
excitation schemes. While the optically detected magnetic resonance (ODMR)
works efficiently between 480 and 580 nm, electrically detected magnetic
resonance (EDMR) shows a strong dependence on the excitation dynamics. The
highest, electrically detected contrast of -23% is achieved by resonantly
exciting the zero-phonon line of the neutral charge state of NV at 575 nm. EDMR
is also enhanced at 521 nm, possibly due to a further excited state of NV$^-$.
