Quick sample of applying customized colors

ColorColumns.json

{
	"$schema": "https://gist.githubusercontent.com/thechriskent/2e09be14a4b491cfae256220cfca6310/raw/eb9f675bf523208eb840c462d4f716fa92ce14c2/columnFormattingSchema.json",
	"elmType": "div",
	"txtContent": "@currentField",
	"style": {
		"color": {
			"operator": "?",
			"operands": [
				{
					"operator": "==",
					"operands": [
						"@currentField",
						"Value1"
					]
				},
				"lime",
				{
					"operator": "?",
					"operands": [
						{
							"operator": "==",
							"operands": [
								"@currentField",
								"Value2"
							]
						},
						"yellow",
						{
							"operator": "?",
							"operands": [
								{
									"operator": "==",
									"operands": [
										"@currentField",
										"Value3"
									]
								},
								"red",
								{
									"operator": "?",
									"operands": [
										{
											"operator": "==",
											"operands": [
												"@currentField",
												"Value4"
											]
										},
										"blue",
										"fuschia"
									]
								}
							]
						}
					]
				}
			]
		},
		"background-color": {
			"operator": "?",
			"operands": [
				{
					"operator": "==",
					"operands": [
						"@currentField",
						"Value1"
					]
				},
				"yellow",
				{
					"operator": "?",
					"operands": [
						{
							"operator": "==",
							"operands": [
								"@currentField",
								"Value2"
							]
						},
						"purple",
						{
							"operator": "?",
							"operands": [
								{
									"operator": "==",
									"operands": [
										"@currentField",
										"Value3"
									]
								},
								"black",
								{
									"operator": "?",
									"operands": [
										{
											"operator": "==",
											"operands": [
												"@currentField",
												"Value4"
											]
										},
										"grey",
										"brown"
									]
								}
							]
						}
					]
				}
			]
		}
	}
}