Novice Snake Owner Questions

[Smileythesnake]

Hello my reptile friends,

Smiley the snake is a 5 1/2 foot long red tail boa and seems to have 2 issues going on that have us perplexed. I look to all of you for input and advice...

1. She has turned a really dark color over the past 3 - 4 days. Normally her tail is really dark red and the rest of her is much lighter. Any idea what might cause this? She appears healthy and happy.
2. She doesn't seem to want to eat. We feed her a medium size rat every 2 weeks and have been trying to feed her for over a week but she shows no interest. When held, she seems her normal inquisative self. Any ideas??

Thanks so much. I would be lost without of all you.

Smiley's Grandmother