In recent years, gradient mapping based on colormaps has gained popularity in image editing and digital painting. However, this mapping often results in the loss of detailed information in the image. In response to this challenge, we propose a method aimed at revealing hidden details without deviating from the original color tendencies of the gradient colormaps. To achieve this goal, we employ a non-linear gradient mapping combined with a generative adversarial network to iteratively adjust the colormap parameters guided by changes in the color space of the image. Through a series of experiments, we demonstrate that our method not only fulfills the desired objectives but also exhibits outstanding performance in color representation.