  We report the first observation of color-suppressed $\bar{B}{}^0 \to D^0
\pi^0$, $D^{*0} \pi^0$, $D^{0} \eta$, and $D^{0}\omega$ decays and evidence for
$\bar{B}{}^0 \to D^{*0} \eta$ and $D^{*0}\omega$. The branching fractions are
found to be ${\cal B} (\bar{B}{}^0 \to D^0 \pi^0) =
  (3.1 \pm 0.4 \pm 0.5) \times 10^{-4}$, ${\cal B} (\bar{B}{}^0 \to D^{*0}
\pi^0) =
  (2.7 ^{+0.8}_{-0.7} ^{+0.5}_{-0.6})\times 10^{-4}$, ${\cal B} (\bar{B}{}^0
\to D^0 \eta) =
  (1.4 ^{+0.5}_{-0.4}\pm 0.3) \times 10^{-4}$, ${\cal B} (\bar{B}{}^0 \to D^0
\omega) =
  (1.8 \pm 0.5 ^{+0.4}_{-0.3}) \times 10^{-4}$, and we set 90% confidence level
upper limits of ${\cal B} (\bar{B}{}^0 \to D^{*0} \eta) < 4.6\times 10^{-4}$
and ${\cal B} (\bar{B}{}^0 \to D^{*0} \omega) < 7.9 \times 10^{-4}$. The
analysis is based on a data sample of 21.3 fb$^{-1}$ collected at the
$\Upsilon(4S)$ resonance by the Belle detector at the KEKB $e^{+} e^{-}$
collider.
