Analyticity and property of an object

Hello Rabbi,
I can’t really understand why the sentence ‘The ball before is round’ is an analytic sentence while the sentence ‘The ball before is red’ is a synthetic sentence.
Ostensibly, the sentence ‘the sphere is round before it’ is analytic because it doesn’t add any knowledge that I didn’t know before, that is, the property of roundness is a property of a sphere. But clearly this is not true, it’s the other way around. In order for me to know that there is a sphere in front of me, I must first be convinced that it is round. The object is only a carrier of properties and as long as it does not have the property of roundness, it cannot be a sphere.
If so, then the sentence ‘the ball before is round’ is no less synthetic than the sentence ‘the ball before is red.’ In both cases, the feature I encountered in reality is what defined what I see.