While browsing my Moldvay Basic last night, I chanced to read the section on light in the dungeon. In particular the part on infravsion where it states warm objects glow red, while cool objects are grey or black! Huh? Back in my 1E and 2E AD&D days, we always went with red for hot and blue for cold. But a check of the 1E DMG shows 'grey and black', while 2E is pretty much silent on the colour as far as I could tell. OD&D and Holmes are, of course, blissfully silent on the whole matter.
So, where the heck did I get blue? Well, that is in fact what it says in the Mentzer books. Now I started with Mentzer, but moved on the AD&D pretty fast. But here is one of those little 'facts' that I never seemed to shake from my first introduction to D&D. Does it matter? No, but it's funny how the ind latches onto these little things after all these years.