  We demonstrate state detection based on coherent Raman repumping and a
two-color Raman state transfer. The Raman coupling during detection selectively
eliminates unwanted dark states in the fluorescence cycle without compromising
the immunity of the desired dark state to off-resonant scattering. We
demonstrate this technique using $^{137}\mathrm{Ba}^+$ where a combination of
Raman coupling and optical pumping leaves the $D_{3/2}$ $\ket{F"=3,m_F"=3}$
metastable state optically dark and immune to off-resonant scattering. All
other states are strongly coupled to the upper $P_{1/2}$ levels. We achieve a
single shot state-detection efficiency of $89.6(3)%$ in a $1\mathrm{ms}$
integration time, limited almost entirely by technical imperfections. Shelving
to the $\ket{F"=3,m_F"=3}$ state before detection is performed via a two-color
Raman transfer with a fidelity of $1.00(3)$.
