Insensitivity of the electron
The electron is not sensitive with the strong interaction, why?
Because it does not utility any.
Indeed, the finality of the interaction strong, also called strong force, is to agglutinate all the quarks and antiquarks of the matter and the antimatter, in sets of the three charges of color: baryons and mesons.
However the electron, elementary particle, doesn't carry neither quark, nor antiquark. Thus it is insensitive with the strong interaction; its three charges of color are linked in a rotation which creates the electric charge.
The end
What do you think about hypothesis, on the structure of the electron, developed in this site?