The ladies at the handbag authentication thread might be able to tell you. Or you can take your bag to an H store and ask them, and compare it with the leather swatches if they have them. Or they might even have a new item in the same leather as your bag. Each leather can look a bit different, even in the same color.
My guess, from color as it looks in this picture, is bleu de malte. That color has a hint of a green tone to while abysse, to me, is a true blue with more purple in it. It's darker than malte. Both are lovely!
What is the date stamp on the front strap, the letter inside a box? Bleu de malte first came out in FW 2010 I believe, and 2010's letter is [N]. So I would think that if the letter is [M] or earlier it should not be bleu de malte. But there always seem to be exceptions. Bleu abysse came out before that but I bet they still made it when Malte was being introduced.
Pierina offered great advice. I would also guess bleu de malte and I have owned H bags in both colors. Bleu de malte has a hint of green undertone, while blue abysse is darker and closer to navy. It can be difficult to distinguish the difference in photos though.
Thank you all for your comments! I thought it was BdM but the production stamp is for 2009. So maybe it is BdP after all?!?! I didn't know BdM only came into production in the fall of 10. So insightful, you ladies!!! Thanks!!!