PURPOSE: The titled composition capable of preventing change in color of an electrically-conductive material of cable, obtained by adding a specific compound as an inhibitor for change in color of the electrically-conductive material to a polyolefin having a t-butyl-containing crosslinking agent and an antioxidant, crosslinking the polyolefin.

CONSTITUTION: A polyolefin having a t-butyl-containing crosslinking agent such as di-t-butyl perxoide, t-butyl cumyl peroxide, t-tutyl cumyl peroxide, 1,3-bis (t-butylperoxy isopropyl)benzene, etc. and an antioxidant [e.g., 4,4'-thiobis-(6- t-butyl-3-methylphenol)etc.] is blended with 0.1W3pts.wt. 4,4-bis-(2,2'-dimethyl- benzyl) diphenylamine as an inhibitor for change in color of an electrically- conductive material. The polyolefin is then crosslinked, to give the desired composition.