Painting Predicament

I'm working on getting the house in shape to sell in a couple of weeks. Patching the walls and painting problem spots -- you know, the regular stuff.

So I go down to the basement and pick a color that matches the walls. Vanillin from Sherwin Williams is a pretty darn close color. I spackle a few holes and paint. Other than the fact I got the wrong sheen (semigloss instead of satin, I though it was shinier) it's a match.

Then I go into the downstairs bathroom.

Nope.

It looks the same to the naked eye, even when comparing the paint chip. It's a textured wall so it's a bit tricky.

Even though it's almost the same, it stuck out like a sore thumb.

Why did the previous owners use almost the same shade of paint?!

Gaaaahhh!!