This document analyzes the process of adding and subtracting selective random noise signals (SRNS) to encrypt and decrypt color images. It discusses converting RGB images to YIQ format to allow adding noise, generating SRNS using an equation with a parameter k to control image quality, and the steps of the encryption and decryption processes which involve adding and subtracting the SRNS. Experimental results on test images show increasing k decreases image quality metrics like PSNR between the original and encrypted images as expected.