Just go for solid colors when possible. You can find sheets in all colors (solids), and etsy is a great place for neutral decor. I'm having a girl but I got a gray and black car seat... a gray and green/yellow high-chair, etc.
For the nursery I did a lot of solids and am adding colorful (gender neutral) artwork to the walls that I found on Etsy. I like it because I can re-use the artwork when/if there is a baby #2 or I give it to a friend later.
Graco has a lot of gender neutral pack n' plays and high-chairs. Chicco for car seats.