Chris Barkan has summarized the problem(s) very well. I hesitate to trust an old slide, how much less can you trust a printed color photo, especially if (as is common nowadays) someone has fiddled the color to please themselves?

Tony Thompson Editor, Signature Press, Berkeley, CA
2942 Linden Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history