Hi,
Mr Color thinner is meant to be used for Gunze enamels (or maybe
lacquers?), NOT for Gunze acrylics. However you can (I have done it) thin Gunze acrylics with Mr Color Thinner. I use it sometimes for weathering to airbrush an almost translucent coat of tpaint, to vary the shade of the base color). However for basic corverage I use
Tamiya acrylic thinner.
HTH,
Christian