Since April 1, 2015, Japan Patent Office has accepted non-conventional trademark applications such as "motion mark", "hologram mark", "color per se mark", "sound mark" and "position mark".
With respect to "color per se mark", althogh more than 450 applicaitions have been filed, no mark has been registered so far.
Please refer to the color mark of trademark application no. 2015-29831 in the name of Hisamitsu Pharmaceutical Co., Inc. This application also has been under examination.