Yes, Memorial Day is the official start to the white season, but this party is all about the color yellow. Yellow is the official color of the armor branch of the U.S. Army, and displaying a yellow ribbon has become an American tradition that shows you await the safe return of a loved one from war.
For tables to eat at:
Go for the all American BBQ feel and cover tables in a red and white checkered tablecloth.
Create centerpieces for the tables by placing short containers of yellow poppies with a mini American flag at the center of the arrangement, down the center of the table.
Use your imagination here! These DIY vases can be anything from refurbished tins to mismatched glasses. The key is to use poppy flowers since they are an important symbol of Memorial Day.
If you plan to eat outside during the evening, intersperse white votive candles with your yellow poppy centerpieces.
For Buffet Tables:
Again, cover your tables in a red and white checkered tablecloth. Place any food in blue bowls and containers.

Designate the end of one of the tables to plates, utensils, cups, etc. Make things easy for your guests and reinforce the theme of this Memorial Day celebration by rolling white utensils in a blue napkin, then tying off with a yellow ribbon.
Place your buffet table against a garage wall or fence, and then hang a pennant banner above the center of the table to create a visual focal point. This doesn't have to be complicated! Keep it simple with a red, white and blue pattern of triangles cut from inexpensive fabric or scrapbook paper, attached to a thick yellow ribbon. Use these homemade banner directions as a guide to craft your own banner.

Under your pennant banner place a large yellow centerpiece. I love Julie Mulligan's latest designs - they're trendy, modern and inexpensive since you're really just concerned with the color of the flower, not the bloom itself.

Another option is her DIY pitcher centerpieces. Julie transformed a few pitchers she had on hand into vessels for summer flowers. Go with her Make Lemonade design for this Memorial Day party. Keep it simple and order this arrangement from 1800Flowers.com or do it yourself by filling a large glass pitcher with water and sliced faux lemons. Then, fill with big yellow and white flowers.
Incorporate yellow ribbons into your space as much as possible! Tie as many of these as you can around your space; place them in trees and on fences. Try to get creative too! Yellow ribbon is inexpensive and would look beautiful tied in big bows on the back of your guests chairs.
Remember to hang an American flag in your space as well!