Photo/IllutrationThe current color scheme for a seismic intensity distribution chart, left, and the new one, right (Provided by the Headquarters for Earthquake Research Promotion)

Quake probability maps and charts are getting a uniform color scheme that is also friendly to those with difficulties seeing certain hues, the central government’s Headquarters for Earthquake Research Promotion announced Aug. 22.

Colors indicating risk level have not been uniform until now depending on the distribution chart. For example, the same black color was used for both high- and low-risk areas.

After the change, the charts will be user-friendly for people with impaired color vision and others by having nine colors correspond to quake probability levels.

The new color code, from the greatest to least risk, will be "reddish purple," “red,” “vermilion,” “orange,” “yellow,” “pale yellow,” “blue,” “light blue,” and “light gray.”

As it is difficult for people with impaired color vision to distinguish between red and green, the colors will not appear together on the same map.

The measures will be introduced to new and newly amended charts.

The headquarters decided on the colors by referring to those used for seismic intensity levels 1 to 7 by the Japan Meteorological Agency.