I have a large collection of train books, and find the Morning Sun books as useful as any.
May I suggest that if it is not in a Morning Sun book, you probably will not find a color shot elsewhere without some heavy duty effort? There are some photo sites on- line that may help - for instance, the Chateau Martin series of tanks is extensively covered and easily found with Google.
I try to find the MS books used, but about 3/4 of my collection came in here at list price, and worth it. Same with most Four Ways West books.