Google Books yields lots of inspiration sources from 19th century primary documents. Primary documents, such as the Les Follets illustrations in this post, show what people actually wore, rather than a what we think they wore. I'm particularly interested in 19th century children's clothing, so I love searching various topics and finding wonderful graphics. Look at this outfit for a child in 1863:
A simple white dress
adorned with red trim
makes a stylish statement:
The same color scheme is used in reverse
a velvet red dress trimmed with white cording
layered over a simple white undershirt or blouse.
Thank you to Google Books for preserving these books and documents so that they are readily available for our research.