The colour of florets and leaves, considerably determining the decorative nature of plants, can depend much on the conditions throughout the period of cultivation. The research analysed the occurrence of anthocyanins and carotenoids in ray florets and chlorophylls in leaves in Chrysanthemum × grandiflorum /Ramat./Kitam., ‘Baton Rouge’ grown in the glasshouse over 2010–2011. The plants were exposed only to short day induced by darkening, applying no supplementary lighting of the plants. From the ray floret tissues carotenoids were extracted using concentrated acetone and anthocyanins with 1% HCl in methanol, whereas to extract chlorophylls a and b from leaf explants, concentrated acetone was used. The samples with extracted pigments were exposed to studies applying the spectrophotometer UV-VIS 1601-PC at the wavelength corresponding to the maximum of the band of a given pigment. For carotenoids the wavelength was λ= 440 nm, for anthocyanins: λ= 530 nm, whereas for chlorophylls: λ= 645 and 663 nm. There was also defined the colour of ray florets and leaves applying the RHSCC Colour Chart [1966]. It was found that the date of plant planting, and thus their flowering, affects the concentration of pigments: anthocyanins and carotenoids in ray florets and chlorophylls in leaves and, as a result, also their colour. The highest concentration of anthocyanins was reported in the plants planted into pots on 1.12., 1.01 and on 1.07., carotenoids in the growing cycles launched on 1.11., 1.12., 1.01, 1.03, 1.07 and 1.08., while chlorophylls a and b – on 1.03.

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