For one frame of reference, the Windsock Datafiles list 26 different shades for PC10 (3E4 through 3E8, 3F4 through 3F8, 4E4 through 4E6, 4F2 through 4F8, 5F3 through 5F6, possibly 5F7, and lastly 5F8) and 5 for PC12 (5F5, 8E8, 8F8, 9E8, 9F8) the last four of which have been rescinded.

I came to the conclusion to differentiate the two on my models I would go with a brownish green for PC10 and a greenish brown for PC12.

Here's my mixes for them:

PC10 Methuen 4F5 Vallejo Model Color 70.924, 70.921, 70.911 mixed in the ratio of 4:1:2 parts respectively.

PC12 Methuen 5F5 Vallejo Model Color 70.826, 70.893, 70.829 mixed in the ratio of 1:3:2 parts respectively.

I went for a mid-range color for the PC10 and the singular 5F5 for PC12. These colors may not be acceptable for everyone, may be completely wrong, or downright ghastly. If someone prefers a different color and has a Methuen code, I would be happy to mix up some Vallejo and share the formula.

Stuart