Ghostscript PDF -> TIFF conversion is awful for me, people rave about it, I alone look sullen

tiffg4 is a black&white output device. You should use tiff24nc or tiff12nc as the output device colour PDFs - see ghostscript output devices. These will be uncompressed but you could put the resulting TIFFs through imagemagick or similar to resave as compressed TIFF.

I have been using ImageMagick for quite a sometime. It's very nice tool with a lot of features.

Install ImageMagick and run following command. This is what I used on Linux, you may have to replace convert with the correct one.

Below command converts PDFs to CCITT Group 3 standard TIFs (Fax standard):

convert -define quantum:polarity=min-is-white \
        -endian MSB \
        -units PixelsPerInch \
        -density 204x196 \
        -monochrome \
        -compress Fax \
        -sample 1728 \
        "input.pdf" "output.tif"

Also you may use GraphicsMagick, it is also similar to ImageMagick, but ImageMagick more concerns with quality than speed.

Like other posts suggested, use a color format (e.g. -sDEVICE=tiff24nc) and specify a higher resolution (e.g. -r600x600):

gswin32c.exe -q -dNOPAUSE -r600 -sDEVICE=tiff24nc -sOutputFile=a.tif a.pdf -c quit