I put this concealer palette and it only has purple and blue and I bought thinking it was concealer
Would it be ok if I used the blue as eye shadow or
Would it look weird?

Most likely, it will be far too creamy to use as eye shadow. Maybe try using a VERY small amount as a base for the same color but personally, I wouldn't use it as only eye shadow.

No way,it will crease and look cakey.If you want that look go for a nude matte eyeshadow.

probably okay. it should look fine as long as you dont use too much!
i mean who uses purple and blue concealer...

if if looks fine then it should be okay, but watch out for creasing if it is creamy