Could we please know the pattern name? Maybe a picture of one of your blocks. Even though we know what you had planned to use, if we can't find something very similar, then we are looking for a needle in a haystack.
Thousandsofbolts.com has many blues to choose from. The creams seem to have some better choices.
https://www.thousandsofbolts.com/index.cfm?fuseaction=product.display&product_ID=204950&ParentCat=57
or this one:
https://www.thousandsofbolts.com/ind...2&ParentCat=57