  Motivated by the recent di-photon excess by both ATLAS and CMS collaborations
at the LHC, we systematically investigate the production and di-photon decay of
onia formed by pair of all possible color exotic scalars in minimal extension.
When such scalar massive meta-stable colored and charged (MMCC) particles are
produced in pair near threshold, $\eta$ onium can be formed and decay into
di-photon through annihilation as $pp\to \eta \to \gamma\gamma$. Squarkonium is
formed by meta-stable squarks in supersymmetric models such as stoponium.
Diquarkonium is formed by meta-stable color sextet diquarks which may be
realized in the Pati-Salam model. Octetonium is formed by color octet scalars
bosons as in the Manohar-Wise model. Stoponium prediction is much smaller than
the required signal to account for the di-photon excess. Due to the enhancement
factor from color and electric charge, predictions of diquarkonium and
octetonium are of $\cal O$(10 fb) which are significantly greater than the
stoponium prediction. Since the color enhancement also results in large
production at the colliders, such light color exotic states of $\cal O$(375
GeV) suffer from severe direct search constraints. On the other hand, if their
dominant decay mode involve top quark, they may be buried in the $t\bar{t}$
plus jets samples and can potentially be searched via $t+j$ resonance.
