An aqueous solution for treatment of colored concrete, glazed enamel or porcelain surfaces to increase the coefficient of friction of that surface, whether dry or wet, to about 0.8 without deteriorating the color of the surface comprises about 1.5 to 1.9 wt % of ammonium bifluoride, 1.5 to 3.0 wt % of tri-ethylamine and a wetting agent in water. The degree of change of the color of the surface, treated seven minutes with the solution of the current application, measured by a color meter shows only 0.56 while the result of a commercial solution to increase the frictional coefficient shows 2.22. This means that the color change by the solution of the current application is undetectable by human eyes. Meanwhile, the change by the commercial solution product is detectable.