Glyng: To the best of my knowledge the Armageddon stuff is the most comprehensive and definitive about Legio Crucius. Obviously, it has no color or emblem info. To be honest, I can't recall where the Praedo Deictus information came from. However, as it references an Imperator titan it was probably published around the TL time period. I've not seen anything updating their information since I put that doc together.
I take that as license to go crazy and make it up the color scheme and symbols you want.
Demi-legio mean that at some point it took massive casualties and has not been rebuilt to full "normal" size (and may never be). Demi- is somewhere around half and Quatro- is about one fourth but legion sizes are non-standard by nature. The closest thing we have is a mention of a newly built legion in
Iron Hands. It lists:
* 1 Imperator
* 40 Warlords
* 24 Reavers
* 16 Warhounds
Crucius should be somewhere roughly in the ballpark of half that.