Doubt shaders simulate tv crt

I use a TVbox with s905x3 4GB Ram + Emuelec 4.6 on a 32" LED TV but the image of SNES, Mega Drive, NES, Mastersystem, N64, Arcade games is not good, which shader do you recommend to simulate the most realistic CRT TV? good color, brightness and contrast

Does using a shader heat up the processor too much and shorten the life of the box?