Within a spontaneously broken color gauge theory of integer charge quarks (icq) one expects standard “confined” QCD predictions for leptoproduction experiments (e.g., μN→ μX) to hold for energies below the threshold for color production; above such a threshold, however, the color degree of freedom must be excited leading to a threshold rise in structure functions. We predict the expected rises for μN and charged current (cc) νN and ν N scattering within the “naive” parton model. Comparing these predictions with the available data on μN, cc νN and ν N as well as e −e + experiments, we deduce that the lightest spin-parity 1 − color octet meson (like the gluon) as well as the lightest color octet ( 8, 8) baryon must lie above 7–8 GeV. This in turn closes the only window in the light mass region <3.1 GeV ( i. e., the 1.1 to 1.8 GeV region), which had so far been left open as a possible value for the physical mass of the gluon. We next observe that the trend of the most recent high- Q 2 high- W Michigan State-Fermilab experiment on μN scattering exhibiting a relatively sharp rise in F 2 above the expectations of confined QCD of order 15% at low x agrees very well with our predictions based on the gauge model of icq. This rise, if confirmed, would favor the hypothesis of gauge icq, and simultaneously imply a threshold for the liberated color octet ( 8, 8) state at nearly (9±0.6) GeV and a mass for the liberated gluon in the region 8 to 9.5 GeV. We remark that within a left-right symmetric gauge structure leading to icq, charged current scattering of laboratory neutrinos ( νN→ μ −X) will excite color only provided that the charged gluons V + mix with V-A gauge particles W L + mrather then with the V+A gauge particles W R +. Thus it is possible that the μN, e −e + and neutral current scattering of neutrinos (i.e., νN→ νX) show signs of color excitation, while the charged current scattering of neutrinos does not. We discuss briefly the implications of the threshold for liberated color octet states possibly lying around 8–10 GeV or higher on future e −e + experiments as well as ν N, ν N, p p- and p p- produced dilepton-search experiments.