Lighting does make a big difference when taking pictures. Here are three different pictures i took of the same towel in different light
Direct Sunlight outdoors
Indoor light by window
Indirect Sunlight outdoors
As you can see, the first picture looks bleached with direct sunlight. The second is too dark, but the last one done in indirect sunlight is much better looking. All I did was crop the images to even them off, then crop again to make the images the same size (square) then re sized the to 900 x 900. You can also add an optional boarder.