Hmm...... Did I miss something? The hidden word has six unique letters anyway......
Hint 1:
Uhh...... I should insert something to make this Nonogram normal. But...... What are they?
Hint 2:
Well, something is definitely off...... By...... What? Speaking of the hidden word, it is a name.
Hint 3:
All numbers are already correct so no need to change them. The board however...... Isn't......
Addendum: There is a (very) minor fix to ensure the puzzle "uniquely solvable", adding 1-light-blue clue on the last position of row 5 and the first position of column 21.
Click the image for a larger version. The colorblind-friendly version is also available here.