Here is a comparison between some of the more commonly-seen bogus notes and their genuine counterparts. Note that all the lettering, signatures, underprints, pverprints and serial numbers are all the same color. See the American Numismatic Association site for more information about reproduction (aka fake or bogus) currency.

1864 Confederate States of America $50 note. Bogus note top, genuine note bottom. Genuine notes are printed on gray or off-white paper. Green underprint. Brown handwritten signatures and serial number.

1864 Confederate States of America $500 note. Bogus note top, genuine note bottom. Genuine notes are printed on thin, off-white paper. Full red patterned underprint. Handwritten signatures in brown (originally black) ink. Stamped serial numbers.

1864 Confederate States of America $1000 note. Bogus note top, genuine note bottom. Genuine notes are printed on white paper. Green underprint. Singatures in (now-)brown ink. Serial number in color. Less than 700 examples were printed. Most show folds.

1863 State of North Carolina $3 note. Bogus note top, genuine note bottom. Genuine notes are printed on white paper. Handwritten signature, date and serial number. usually aged to a soft brown. Most examples show numerous folds.

1862 State of Mississippi $100 note. Bogus note top, genuine note bottom. Genuine notes are printed on thin white paper. Rusty orange underprint. Handwritten signatures, date and serial number. Most handwritten ink is aged to brown.