When someone ruins your day they have steyned your day with shit / made it worse. Because it is not a physical stain it has 'steyned' your day in a mental sense.

A Bloomer is someone with a bright outlook on life who is optimistic in nature. Bloomer's frolic in every opportunity to be happy and try to make the most out of life. The opposite of a Bloomer is a Doomer. The term Bloomer originated specifically as a counter to the Doomer on sites especially like 4Chan.