Hot pink or lime green...just a thought.

Yellow

The problem with a "white" cloth and white dishes is there are shades of white. If the cloth and dishes are the same white, I would love that with the cobalt blue and white dishes and runner> If you can't get a white match....how about a St Patrick's day green?

I have a lot of "blue willow". In quotes because some is legit and some is Ikea, thrift store, etc. I use this in a pre civil war home with a dining room table that is bar height. In other words it isn't so traditional. I use a denim blue background most of the time but for you I would go with spring colors

There isn't a background that Blue Willow will not work with. I'd pick a strong spring color.

I just did a Google image search for Blue Willow tablescapes. There is a lot of white but there are some other interesting choices. I like the blue awning stripe.

Blue Willow tablescapes

The ones on a blue-and-white print are pretty, and could unify the white dishes. Or, you could use simply white, and add blue mats under the white places, and white mats under the blue places. Or, among the pictures, I love the white tablecloths with the bright green or cobalt or orange accessories (napkins, chargers, centerpieces, salt-and-peppers, etc) Simple and striking.

How about that Blue Willow wedding cake in the pictures?! Stunning!

Blue Willow is almost a neutral and would work with almost any color. For a seriously formal occasion, only white or ecru linens are acceptable. For a more relaxed event, the entire color spectrum is available to you, including patterns, although mixing patterns is a little bit trickier than using solids. I love the search results, D_gw, pulled. The settings with grass green or petal pink reflect the essence of spring to me.

I would go ecru, sand, or cream. I have a lot of neutral tablecloths because they are so flexible. I use runners and place mats to spice up the look and set off the plates. That allows me to use different colors depending on the season, and mix and match. How neutral is the room you are setting this up in?

I carried around a 17th century blue and white Chinese plate to different colored pillows and fabrics and it looked really great against a soft apple green background. Surprisingly it also looked good against shiny soft gray material and a muted red. White seems really insipid. It's such a strong pattern that it needs something fairly strong to stand up to it, but also in some sense muted so that they don't scream at each other.

I did a St Patrick's Day dinner party a few years back....and while I don't have blue willow, I do have a white china with a wide blue band.
I used a white cloth, and very bright leaf green linen napkins and tied a green ribbon bow on each stemmed glass and on the cahdlesticks and 3 little pots of shamrocks down the center of the table....LOL! It was very St Paddy's day....but my point is the green and blue, when relieved with white looked great!

I don't have blue willow but I have blue and white transfer ware and I think that blue and white is a neutral and goes with anything -- pinks, all shades of green, orange, red. I usually use a white lace cloth and white damask napkins -- but them I'm a traditionalist. I get color in the floral centerpiece and perhaps other elements I use as part of that centerpiece.

I'd like it on a very pale blue. Though as others have said, it is a neutral and can go on anything. A red tablecloth would be stunning. Maybe decide based on what seasonal flowers are available. If daffodils are around, how stunning with yellow!

I think a yellow and white or dark blue and white stripe would be pretty. Or, a stripe with a mix of blue and yellow

How fun!

Rats! Now I want a set! DH would have kittens if I bought more dishes!

I also think Blue Willow is just stunning on a soft, lighter blue. So fresh and pretty!

Or a pale pink?

I have a set of Blue Danube, bought when I first moved into my house when I was 26yrs.old. They've been hardly used, packed away in a box. You've made me consider getting them out now that I see these pretty tables. Except, they aren't as durable as my Walmart white ironstone. ha. A white or yellow cloth would be nice.