Most product listings recommend leaving the all‑over L'Oréal Excellence Crème blonde color on for 25 minutes. One listing shows a 35‑minute processing time, so the documented range in the details is 25–35 minutes.
Apply the mixed color to dry, unwashed hair. For all‑over color: leave on for 25 minutes, then rinse and condition for 2–3 minutes. For root touch‑ups: apply to new growth and leave for 20 minutes (add 5 minutes for resistant grays), then apply the remaining product to the lengths for an additional 5 minutes so total processing equals 25 minutes.
Most product details list the color as suitable for all hair types. One listing specifically calls out suitability for curly and previously colored hair as well.
Product details state 100% gray coverage, including on stubborn grays.
Most kit listings show a net volume of 6.3 fl oz (US).