Isaiah 64:6 But we are all as an unclean thing, and all our righteousnesses are as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away.
These are works of people who are doing iniquity, they do their own righteousness
There are two righteousness in the Bible, which are God's righteousness and man righteousness
Romans 10:3 For they being ignorant of God's righteousness, and going about to establish their own righteousness, have not submitted themselves unto the righteousness of God.
God's righteousness is justice while man's righousness is the righteousness God made themselves
Romans 3:10-12 As it is written, There is none righteous, no, not one:
There is none that understandeth, there is none that seeketh after God.
They are all gone out of the way, they are together become unprofitable; there is none that doeth good, no, not one.