I'd like to paint a pixel art mural using the Paint Roller. I would like to use a background with the least amount of texture "noise" so the colors of the pixel art stands out the most. To illustrate, here are several pre-hardmode background tiles painted sky blue:
(cactus, dirt, mahogany, bone, mushroom, stone, wood)
Based on this limited sample, dirt walls out of everything seem to do alright:
However this is not even close to all available walls in the game. Which wall is the most plain and makes colors the most vibrant?