I compared the identified value range of JAAF #1 Hairyokushoku (Ash Green Colour) to Thorpe's identified Army colours and at first glance there seemed to be little correlation. The upper picture shows the #1 value range as a gradient in the top chip and below it the two closest Thorpe colours also rendered as a gradient. Both A4 Light Green and A5 Light Grey Green are described as being used for the upper and lower surfaces of Army aeroplanes.
When I calculated gradients of the #1 low end value to Thorpe's A5 and the #1 high end to Thorpe's A4 a different picture emerged. The gradiated chips are shown in the lower image. This suggested to me that the Thorpe colours are variations of the same colour and in turn variations of the standard Army #1 Hairyokushoku.
Image credit: rendered colours © Straggler 2008