Welcome to the Boards!!
I too agree with the others ... do what you like! There are no rules!
Contrasting thread can make for a lovely effect. Although it can also look disastrous.
It really depends on the effect YOU want and what YOU like!
One of the nicest baby quilts I have seen was a white background with variegated thread (blues-white) cross hatched. It was subtle and broke up the constant white quite nicely. That one really sold me on variegated thread use. Likewise, some of the loveliest wholecloth hand quilting I have seen has been coloured thread on white or cream.
You have already tried pooling your thread and like it.
If you want further confirmation, do a test piece of the same fabrics and threads with you are considering. Then make your decision.