Answering to myself: They almost certainly did. There's only 16 colors in the final image: $ curl -s https://i.redd.it/wc436nf7fdpy.png | pngtopnm | ppmhist

Answering to myself: They almost certainly did. There's only 16 colors in the final image: $ curl -s https://i.redd.it/wc436nf7fdpy.png | pngtopnm | ppmhist libpng warning: iCCP: known incorrect sRGB profile r g b lum count ----- ----- ----- ----- ------- 34 34 34 34 258550 255 255 255 255 154487 229 0 0 68 123218 0 0 234 27 90720 229 217 0 196 63755 229 149 0 156 55643 2 190 1 112 40918 0 131 199 100 32930 0 211 221 149 29820 255 167 209 198 28576 228 228 228 228 27733 136 136 136 136 26035 130 0 128 54 20019 160 106 66 118 18023 148 224 68 183 16047 207 110 228 153 13526