Memo Deduction - Hardest Game for Geek of  IQ, Mathematics and Logic

Geek, GPA Top 5, Mathematical Olympiad Winner come and challenge it!!!
Your brain becomes slow and stops working? Come and brainstorm!!!

Try our Memo Deduction:

Deductive out the 4-5 memos color according to the hints;
Click each memo to select a color or leave blanks, click done;
Red pushpin numbers means the color & position are both right numbers, the black means the color is right but position is wrong ones.
Hint: The grey color=blank

3 levels:
Easy: 4 memos, 3 colors, 8 chances
Normal: 5 memos, 4 colors, 8 chances
Hard: 5 memos, 5 colors, 7 chances