Rain has a strong attenuation effect on light, which can impact the performance of visible light communication (VLC). In this paper, we addressed the crucial challenge of implementing high-speed VLC systems in rainy environments by focusing on the performance of different wavelengths under varying rain conditions. By analyzing the attenuation characteristics of four laser diodes at different wavelengths under various artificial rain environment, we developed a high-speed VLC system optimized for rainy channels high-speed visible light communication employing the orthogonal frequency division multiplexing modulation scheme. Through the integration of channel-adaptive pre-equalization and bit-loading algorithms, our system optimized signal transmission in rainy channels, enabling an aggregated data rate exceeding 30 Gbps, which was the highest reported data rate for VLC in the rainy channels.