Paldalmun gate was built in 1794 as the southern gate of Suwon Hwaseong. The signboard’s paintworks of Paldalmun gate was applied to the signboard of the state-run building in the 18th century. The signboard of Paldalmun gate was repainted along with the building when repaired in 1969. In that time, the signboard’s paintworks during the reign of Jeongjo era was transformed. The purpose of this study is to restore the image of Jeongjo era paintworks on the Paldalmun’s signboard, which has been modified since the 1960s due to modification. For the purpose of the examination, we examined the traces of paintworks remaining on the signboard of Paldalmun gate and examined several state-run signboards decorated with ‘Yukhwamoon’ paintings similar as the signboard of Paldalmun gate, which made around the 18th century. Through the above-mentioned researches, typical color features were identified in the decorated with ‘Yukhwamoon’ paintings on signboard in the 18th and 19th centuries. In addition, the type of pigment used in the signboard’s paintwork of Paldalmun gate was verified through the 『Hwaseong Seongyeok Uigwe(華城城役儀軌)』 and the 『Han-gul Jeongri Uigwe(한글整理 儀軌)』, while analyzing the characteristics of age-related deterioration according to the type of paintworks in various traces of pigment coatings remaining on the signboard of Paldalmun gate.