Thanks for the photos Lyric1, from what they show I may have to have a rethink on my interpretation of Minnesota Mauler. The last photo shows that the cowl rims and the number or number square colours were used as squadron identifiers. So if the cowl rims and numbers are yellow (or white) on Mauler, then presumably the darker shaded tail and nose art were indeed red as per the profiles etc. This would mean that all 451st BG NMF aircraft had red tails and that the very pale appearance of the tail colour on some black and white photos was down to fading, some sort of artefact of the film used, or a trick of the light. This doesn't seem likely to me though, some aircraft have tail colours that are much lighter than the NMF.
Unfortunately both the colour photos show aircraft 59 and 61 which not only had red tails but red number surrounds and cowl rims. What is needed is a photo that clearly shows a red tail with different colour cowl rims and numbers. The third aircraft in line on the last photo shows the number 62 on the nose in a green square and with green cowl rims, so it seems that by this time the number used did not denote the squadron.
All in all, it is a bit confusing.