Hair colour

Melanin levels (only two of those can be on "high" at once, one from the father and one from the mother):

• Black Eumelanin (white to black)
• Brown Eumelanin (white to yellowish brown)
• Pheomelanin (white to red)

Pseudo-genes encoding this:

• [BTB] Black-to-Brown Eumelanin balance (black - brown - yellowish brown)
• [EMA] Amount of Eumelanin (white - fully coloured)
• [PMA] Amount of Pheomelanin (white - red)
• [BMA] Amount of black Eumelanin (white - black)

EMA gene is the same as for eye colour, so that dark brown eyes can't appear with light hair (brown and amber eyes still can, by a combination of low EMA level and high STP levels in eye colourisation)

Typical combinations:

• Black Eumelanin only -> Black
• Brown Eumelanin only -> Brown
• Pheomelanin only -> Red
• Black Eumelanin & Pheomelanin -> Chestnut Brown
• Brown Eumelanin & Pheomelanin -> Auburn
• low amount of all -> Blonde
• negligable amount of all -> White

Additional notes

Common MC1R (melanocortin 1 receptor; 317 positions) gene (chromosome 16q24.3) variants:

• N29insA - red
• Phe45Leu (rs61996344)
• Ala57Val (rs117952179)
• Val60Leu (rs1805005) - blonde
• Arg67Gln (rs34090186)
• Ser83Pro (rs34474212)
• Asp84Glu (rs1805006)
• Gly89Arg (rs34540312)
• Val92Met (rs2228479) - red
• Thr95Met (rs34158934)
• Leu99Pro (rs192276807)
• Gly104Ser (rs2229617)
• Ile120Thr (rs33932559)
• Arg142His (rs11547464)
• Arg151Cys (rs1805007) - red
• Arg151Gly (rs1805007)
• Arg151His (rs149922657)
• Y152OCH
• Ile155Thr (rs1110400)
• Val156Leu (rs3212365)
• Thr157Ile (rs104894524)
• Pro159Thr (rs104894523)
• Arg160Trp (rs1805008) - red
• Arg142His (rs11547464) - red
• Ile155Thr (rs1110400)
• Val156Leu (rs3212365)
• Thr157Ile (rs104894524)
• Pro159Thr (rs104894523)
• Arg160Trp (rs1805008)
• Arg163Gln (rs885479) - blonde
• Ala166Gly (rs35040147)
• Ala171Ser (rs35784916)
• Phe196Leu (rs3212366)
• Leu211Val (rs188462456)
• His260Pro
• Thr272Met (rs12102534)
• Asp294His (rs1805009) - red
• Thr314Thr (rs2228478)

Uncommon variants:

• Arg307Gly - Neanderthal variant
• Phe147Delta

OCA2 gene (chromosome 15q11.2–12) variants:

• Arg305Trp (rs1800401)
• Arg419Gln (rs1800407) - red
• rs16950821
• rs7174027
• rs4778138 - brown
• rs4778241
• rs7495174

ASIP (agouti signaling protein) gene variants:

• rs1015362 - blonde-red
• rs6058017
• rs2378249

HERC2 (hect domain and RLD 2) gene variants:

• rs12913832 - black
• rs7183877
• rs11635884
• rs916977 - red
• rs8039195 - red

SLC45A2 gene variants:

• rs16891982 - black
• rs28777 - black
• rs26722 - black

IRF4 gene variants:

• rs12203592 - black
• rs9378805

EXOC2 gene variants:

• rs4959270 - black

TYRP1 gene (chromosome 9p23) variants:

• rs1408799
• rs2733832
• rs683

TYRP2 gene (chromosome 13q31–32) variants:

TPCN2 gene variants:

• rs35264875
• rs3829241
• rs2305498
• rs1011176

TYR gene (chromosome 11q14–21) variants:

• Ser192Tyr (rs1042602)
• Tyr192Ser - albino?
• Arg402Gln (rs1126809) - albino?
• rs1393350 - brown

KITLG gene variants:

• rs12821256

SLC24A4 gene variants:

• rs12896399
• rs4904868 - blonde
• rs2402130 - dark blonde