  We demonstrate significant enhancement of frustrated double ionization (FDI)
in the two-electron triatomic molecule D$_{3}^{+}$ when driven by
counter-rotating two-color circular (CRTC) laser fields. We employ a
three-dimensional semiclassical model that fully accounts for electron and
nuclear motion in strong fields. For different pairs of wavelengths, we compute
the probabilities of the FDI pathways as a function of the ratio of the two
field-strengths. We identify a pathway of frustrated double ionization that is
not present in strongly-driven molecules with linear fields. In this pathway
the first ionization step is "frustrated" and electronic correlation is
essentially absent. This pathway is responsible for enhancing frustrated double
ionization with CRTC fields. We also employ a simple model that predicts many
of the main features of the probabilities of the FDI pathways as a function of
the ratio of the two field-strengths.
