In this study, a new high-capacity, low-distortion, and reversible data hiding method based on RGB that hides color images inside color images is proposed. The proposed method divides the 24-bit image into 8-bit (1byte) meaningful segments, and the first most important 4 bits of the 8-bit data are hidden directly while the less important negligible 4-bit is not hidden and it is completed by rounding at approximate value through the function. The first 4 bits hidden in extraction are combined with the 4 bits from the function to retrieve 1 byte of information. In this way, since the 8-bit data is reduced to 4 bits, the method performs lossy hiding. Since the size of the data reduces by half owing to this method, it offers twice the capacity compared to the traditional LSB methods. When the same amount of data is hidden, the method creates lower distortion in the cover image than traditional LSB methods. Peak signal to noise ratio (PSNR) and structural similarity quality criterion (SSIM), which are frequently used in the literature, are used to measure the image quality of the proposed method. The test results showed that the proposed method achieved twice as much capacity in comparison to the traditional LSB method, higher efficiency than the studies in the literature, and higher PSNR and SSIM values as undetectable are obtained.