It isn't uncommon to use terminology that calls the force between hadrons in a nucleus the "strong nuclear force" or the "nuclear force" and calls what has been called the "color force" above the "strong force."
Indeed, the force mediated by gluons between quarks is usually called the "strong force" and not the "color force" despite the confusion that this can create between that force and the one between protons and neutrons in a nucleus mediated mostly by pions which is a residual effect of the force between quarks mediated directly by gluons. For example, the coupling constant of the force mediated by gluons is commonly abbreviated alpha with a subscript "S" for "strong" and is called the strong force coupling constant.
"is it correct to call the color force "tripolar?" On account of the three "charges" of the color force, "red," "blue," and "green?"
Sort of.
While quarks can have one of three color charges, antiquarks have one of three anti-color charges, anti-red, anti-blue or anti-green. And, while gluons in a crude sense are composed of a color charge paired with an anti-color charge, there are actually only eight distinct combinations of color charges in gluons, not nine. This is because the crude way of discussing color charge that I have just used isn't really perfectly accurate for describing permutations of color combinations in gluons in the SU(3) group of QCD.
Of course, it also bears noting that all of the color charges are merely theoretical accounting tools used in QCD calculations and are not themselves ever observables. No scientific instrumentation in existence (or even theoretically imagined) can tell you the particular color charge of a particular quark, anti-quark or gluon. All hadrons are "color neutral" and all quarks and anti-quarks except pairs of top quarks and anti-top quarks (which are assumed to have a corresponding color and anti-color when produced) are confined in hadrons. Also, while "charge" is the usual way to describe a "color charge", there are isolated instances I have seen in publications where color charge is viewed as something more analogous to a polarization or parity than to an electro-magnetic charge (although it isn't any of these things, of course).
We infer the number of colors mostly from the kinds of combinations of quarks and anti-quarks that are observed (and not observed) in hadrons (i.e. composite particles made up of quarks, antiquarks and gluons), from the branching fractions of different decays of those hadrons that are observed, and from the fact that any given quark is three times as likely as any given lepton to be produced in W and Z boson decays at tree level. Color neutrality of hadrons provides that the three simplest color neutral configurations are three color baryons, three anti-color anti-baryons, and color-anticolor pair mesons, although it also allows for example, for tetraquarks and pentaquarks which are just starting to be observed experimentally.
In the same vein, it is also worth noting that there are generalized Yukawa interactions similar to QCD in which one can change the formulas involved by varying the number of colors and the normal of fermion flavors (i.e. the equivalent of the number of distinct kinds of quarks). For example, one can easily determine the formulas that would apply in a world with four colors and eight quark flavors instead of six. In Lattice QCD it is common to do calculations with a variety of number of color and number of quark flavor variations to estimate the real world value by showing trend lines as the number of colors and flavors change, since the real world values turn out to be very hard to calculate at. (The mass of a hypothetical pion is also often varied to show trend lines and make estimates, usually using values greater than the real world 140 MeV and working one's way towards lighter more realistic values.) Indeed, in low energy interactions where energy-conservation prohibits the creation of heavy quarks except in highly suppressed virtual loops, it is appropriate to do the equations of real world QCD with fewer than all 6 quark flavors. A 2+1 scenario that assumes an up and down quark of identical negligible mass and a strange quark, is particularly common for many Lattice QCD calculations.
