Colors in nature seem to be almost unlimited. Yet, spectral imaging of natural scenes has revealed that the colors around us are limited to just a couple of million which is only a small part of the colors our visual system can perceive [1]. Daltonics perceive even fewer colors.
Theoretical estimates predict that anomalous trichromats can see 50% of the colors seen by normal individuals and dichromats less than 1% [2].
Empirical data has shown, however, that in natural scenes dichromats are little impaired as they can discriminate almost 70% of the colors perceived by normal individuals [3]. Another remarkable result revealed by spectral imaging is the enormous variation in the color of the illumination across natural scenes [4]. Nevertheless, normal individuals and daltonics exhibit a notable degree of color constancy [5].
Natural color statistics seems to be mimicked by artists in paintings.
At least in one aspect, however, natural scenes and paintings seem to differ systematically: the color gamut of paintings is generally more biased towards the red in paintings than in natural scenes [6]. But experiments on aesthetics of occidental and Japanese paintings showed, quantitatively, that the non-naturalistic nature of the gamut orientation does not constraint in any way its aesthetic value [7].

  [1]Linhares, Pinto & Nascimento,  J. Opt. Soc. Am. A, 25, 2918-2924 (2008).
  [2]Perales, Martínez-Verdu, Linhares & Nascimento,  J. Opt. Soc. Am.
A, 27, 2106-2114 (2010).
  [3]Nascimento, Linhares, Pastilha, Santos & de Almeida, Journal of Vision, 16(12):638-638 (2016).
  [4]Nascimento, Amano, Foster, Vision Research, 120, 39–44 (2016).
  [5]Álvaro, Lillo, Moreira, Linhares, & Nascimento, Journal of Vision,
15(12): 406 (2015).
  [6]Montagner, Linhares, Vilarigues, & Nascimento J. Opt. Soc. Am. A, 33, 178-183 (2016).
  [7]Nascimento, Linhares, Montagner, João, Amano, Alfaro, & Bailão, Vision Research, 130, 76-84 (2017).