I think you need another color. Maybe navy?

The green walls are very green and dominant, so I would use more of a compliment color with less green. Too much green in the room will just make you measurable. What ever you choose, just don't add flowers, men hate flowers.

You have many suggestions from these talented ladies. I would love to see the quilt that you make.

Plaid fabrics tend to make any pattern masculine, imho.

What about any hobbies your husband has? Include some prints of thoses - fishing, motorcycles, reading OR work type prints - trucks, shields (for police officers/firefighters), etc.

If you want a precut, Kansas Troubles uses that same green in their fabrics. Moda produces their fabric lines.

A Carpenter Star is a beautiful quilt pattern.

Forgot to say, I would use lighter colors, like cream to make it pop with the room color, combined with a coordinating browns or tans -- choose three colors for the Carpenter star and make one of them cream.

Quilt for husband
 

What about making the Big Star Quilt? Here's a link to Jenny Doan's tutorial on this quilt using the Orchard House precuts by Windham. Also, what about the La Belle Fleur collection by French General / Moda? There is a lot of sage/cream/burgundy colors in it. Good luck. Hope to see a picture of the finished product.:o

The first thought that came into my mind when I saw your hunter green walls is a Irish Chain quilt. It is a gender neutral patterns, I think. Green and white would be lovely in a Irish Chain pattern.