Well, finallement, having no help, I reinstalled the version 2.1.2 of NextGEN Gallery what résoud the problem number 1.
But the problem number 2 (colors) always persists. If somebody could help me I does not understand.
Same problem for me
→ http://www.adelphe-photographies.fr/
WordPress 4.1.1
NextGEN Gallery 2.0.66.37
NextGEN Pro 2.1.4
NextGEN Gallery Voting Premium 1.6.1
Gallery used : NextGEN Pro Thumbnail Grid With ECommerce
