This paper presents a load estimation method using a mechanochromic hydrogel sheet. The structural color of the gel is changed depending on the applied pressure to the gel sheet. The proposed load estimator based on the combined approaches with image features and machine learning can detect the applied load from the captured images of the gel sheet. The extracted image features of the color images of the gel sheet are superimposed on the captured initial images. By using the superimposed images as input to the machine learning system, we improve the success rate and precision of the load estimation. The experimental results show that the estimator recognizes the applied force with every 100 gf from 0 to 1,000.