What color is your backing? I prefer not to have a strong contrast between thread and fabric. I think white or yellow thread would work well for this quilt. I would recommend working with a practice sandwich before starting in on the quilt itself.

I used to stitch with stark white, and after a while decided that I did not like it. I now use off-white, or a light cream.

I have hand quilted a few projects and have use a variety of threads. It really depends on what effect you want in your finished quilt. If you want the quilting to really show then used something with a high contrast to the fabrics. I have used different colors on different areas of a quilt just so the color from the thread can be seen and add to the design elements. I have used 2 stands of embroidery floss in some projects because the color was closest to what I wanted. I have used pearl cotton and bigger stitches on a whole cloth piece that really makes the colors of the thread "pop." I have also used variegated hand quilting threads as well as white/neutral, There are as many choices as there are quilts and quilt-makers.
Also, it may depend on the quilting design that you choose. You may want to pick one color that blends with or contrasts with all the colors if you are doing an overall pattern. Or if you are going to quilt something within the strips you may want to use a different color in each color of strip to get the effect that you want.
BTW-your quilt top is very lovely. So sunny and happy! Good luck-I know you will enjoy the process what ever you pick!

Another sometimes hand quilter here. I started out using just cream. But for the project I'm working on now I'm using turquoise glazed thread on something with turquoise, brown and white. It is looking good. so, like everyone above says, do what you find pleasing!!

That is what I would do also.

If your thread is the same color as the fabric, the stitches don't stand out so much. For a beginning quilter, this might be a good thing as stitch consistency takes practice to accomplish. Contrasting thread shows every stitch flaw.

Edited to tell you that your quilt is lovely.

beautiful quilt. I hand-quilt and only use YLI glazed cotton thread. I do have to order it online, but it is quick to arrive. I like cream color for most quilts - even stark white quilts, the cream works well. It's also priced very reasonably.

I tend to pick something that goes w/ my backing. I believe the type of batting I pick almost accentuates my quilting more than the thread. I like the crinkled up look that a quilt gets after washing it. My current project has Hobbs 80/20 batting. First time i've used it, so i'll be interested to see how it washes up.

And for your quilt - I see a cream color.

I use the same thread I pieced it with which in my case is neutral tan. It doesn't smack you in the eye but does show the quilting nicely. For blues I'd probably use a light grey.

I have been hand quilting for at least 4 years now and my stitches never look consistent. I do get frustrated because I try to keep things consistent but eventually give up. I enjoy the hand work so to quote my DD, "It is what it is."
I see a yellow quilting thread on this one.
However, I agree with Bree123, if I am putting in all that time to hand quilt, I darn well want others to see it and KNOW that it is hand done.

when I started hand quilting in the early 70's ( before that I tied quilts with emb floss) i used white or off white. that was what they had that I could see. Now that quilting is popular, it comes in all colors. I use colors that match,, but on a bright colored quilt, i used bright colors in the black borders. I'd go with yellow on this lovely quilt, and them maybe accent with an orange. again, it's all up to you. I love this quilt you made.