I used warm ones on my rear number plate, they are warm but not yellow like the incandescents. Some LEDs are a horrible colour or dim but you can't really tell until you try them - that's why I have a drawer full at home.
Try ebay, I just searched the type of bulbs and the word warm.
e.g. "warm t10" or "warm w5w"
They also have lots of aliexpress.
I used these for the spotlights in the bottom of the mirror:
http://www.dx.com/p/pointpurple-t10w...ar-lamp-171856
They are not warm, but they are perfect colour rendition white, and focus the light into a tight pool just where you need it to read etc..