Orange, Longbottom.

This is your copy of Advanced Potion-Making, is it, Potter?”
“Yes,” said Harry, still breathing hard.
“You’re quite sure of that, are you, Potter?”
“Yes,” said Harry, with a touch more defiance.
“This is the copy of Advanced Potion-Making that you purchased from Flourish and Blotts?”
“Yes,” said Harry firmly.
“Then why,” asked Snape, “does it have the name ‘Roonil Wazlib’ written inside the front cover?”
Harry’s heart missed a beat. “That’s my nickname,” he said.

There is no point in apportioning blame. What is done, is done.

Always

But I don’t think I’ve ever known such a natural at Potions!” said Slughorn. “Instinctive, you know — like his mother! I’ve only ever taught a few with this kind of ability, I can tell you that, Sybill — why even Severus —”
And to Harry’s horror, Slughorn threw out an arm and seemed to scoop Snape out of thin air toward them.

There are all kinds of courage, it takes a great deal of bravery to stand up to our enemies, but just as much to stand up to our friends. -Albus Dumbledore referring to Neville Longbottom-