[Shadow_]

Simple, But Good.

You could make it so when the player connects they get a random colour and the they can type /pcolor [1-100] and they get a different one.

Code:

new PlayerColors[100] =
{
	0xFF8C1340,0xC715FF40,0x20B2AA40,0xDC143C40,0x6495ED40,0xf0e68c40,0x77889940,0xFF149340,0xF4A46040,0xEE82EE40,0xFFD72040,
	0x8b451340,0x4949A040,0x148b8b40,0x14ff7f40,0x556b2f40,0x0FD9FA40,0x10DC2940,0x53408140,0x0495CD40,0xEF6CE840,0xBD34DA40,
	0x247C1B40,0x0C8E5D40,0x635B0340,0xCB7ED340,0x65ADEB40,0x5C1ACC40,0xF2F85340,0x11F89140,0x7B39AA40,0x53EB1040,0x54137D40,
	0x27522240,0xF09F5B40,0x3D0A4F40,0x22F76740,0xD6303440,0x9A698040,0xDFB93540,0x3793FA40,0x90239D40,0xE9AB2F40,0xAF2FF340,
	0x057F9440,0xB9851940,0x388EEA40,0x02815140,0xA5504340,0x0DE01840,0x93AB1C40,0x95BAF040,0x36997640,0x18F71F40,0x4B898740,
	0x491B9E40,0x829DC740,0xBCE63540,0xCEA6DF40,0x20D4AD40,0x2D74FD40,0x3C1C0D40,0x12D6D440,0x48C00040,0x2A51E240,0xE3AC1240,
	0xFC42A840,0x2FC82740,0x1A30BF40,0xB740C240,0x42ACF540,0x2FD9DE40,0xFAFB7140,0x05D1CD40,0xC471BD40,0x94436E40,0xC1F7EC40,
	0xCE79EE40,0xBD1EF240,0x93B7E440,0x3214AA40,0x184D3B40,0xAE4B9940,0x7E49D740,0x4C436E40,0xFA24CC40,0xCE76BE40,0xA04E0A40,
	0x9F945C40,0xDCDE3D40,0x10C9C540,0x70524D40,0x0BE47240,0x8A2CD740,0x6152C240,0xCF72A940,0xE5933840,0xEEDC2D40,0xD8C76240,
	0x3FE65C40
};

//OnPlayerConnect

SetPlayerColor(playerid,PlayerColors[playerid]);

Simple code to make it when a player connects he/she gets a random colour.