PROBLEM TO BE SOLVED: To provide a judging method of colorific youthfulness of lips, a powder composition for a lip cosmetic that excellently improves appearances-color tones of lips so that appearances-color tones of lips darkened by ageing or the like are improved to look vivid and youthful and that appearances-color tones do not look strange when it is applied to originally vivid and youthful lips, and a lip cosmetic comprising the same.SOLUTION: The method for judging colorific youthfulness of lips comprises using as an index the difference between the a* value and the b* value obtained by converting an RGB data of images of lips photographed with a camera to the L*a*b* color specification system. The powder composition for the lip cosmetic has a sample variance (&sigma2) of at most 30, where the samples are each a value of a difference spectrum obtained by measuring a spectral reflectance of diffusion reflection, including specular reflection, of a powder on a white paper and a powder on a black paper for predetermined wavelengths within a wavelength range of 400-780 nm by an ultraviolet-visible spectrophotometer attached with an integrating sphere unit. The lip cosmetic comprises the powder composition.COPYRIGHT: (C)2010,JPO&INPIT【課題】口唇の色彩的若々しさの判定方法、加齢等でくすんだ口唇の外観・色調を改善し、鮮やかで若々しく見せ、もともと鮮やかで若々しい口唇に塗布しても外観・色調が不自然に見えない、口唇の外観・色調を改善することに優れた口唇化粧料用粉体組成物とこれを含む口唇化粧料を提供することである。【解決手段】カメラで撮影した口唇画像のRGBデータからL*a*b*表色系に変換し得られたa*値とb*値との差を指標として口唇の色彩的若々しさを判定する方法と、積分球ユニットを取り付けた紫外可視分光光度計で波長400nm~780nmの範囲で白色紙上の粉体と黒色紙上の粉体の正反射光を含む拡散反射光の分光反射率をそれぞれ測定し差スペクトルを求め、得られた各波長の値を標本とし、求めた標本分散(σ2)が30以内であることを特徴とする口唇化粧料用粉体組成物及び当該粉体組成物を配合してなる口唇化粧料。【選択図】なし
