[Chimera-users] RR distance map, scale normalization

Hi, I am comparing four drug bound structures of homologous proteins to their unbound structures in chimera RR distance maps. These structures vary to different degree to unbound structures and I want to show that in four individual RR distance maps (each bound structure to unbound structure). The problem is that the scale varies each time and I was wondering if there is a way to normalize the scale? or set the color code so that, for e.g, for stdv of 10 its red in all cases and below 5 its always white. Thanks. Best wishes, Arvind.