During the inspection of rubber insulating gloves, which of the following is NOT a defect to look for?

When inspecting rubber insulating gloves, it is crucial to identify defects that could compromise their effectiveness in protecting against electrical hazards. Among the options provided, colorfastness is not considered a defect that significantly affects the glove's protective capabilities.

Ozone cutting refers to the deterioration caused by exposure to ozone, which can create small, microscopic cracks that weaken the material of the gloves. Softening of the rubber can also indicate degradation, leading to loss of insulation properties. Punctures are critical defects that can allow electrical exposure and must be avoided entirely.

In contrast, colorfastness is more related to the aesthetic aspect of the gloves—whether the color will fade or change when exposed to various conditions—rather than their protective function. Therefore, while it may be a consideration for the overall appearance, it does not pose a direct hazard to the user’s safety in the context of electrical insulation.