jsoncolor is a drop-in replacement for encoding/json's Marshal and MarshalIndent functions and Encoder type which produce colorized output using fatih's color package.

go get -u github.com/nwidger/jsoncolor

To use as a replacement for encoding/json, exchange

import "encoding/json" with import json "github.com/nwidger/jsoncolor".

json.Marshal, json.MarshalIndent and json.NewEncoder will now produce colorized output.

The colors used for each type of token can be customized by creating a custom Formatter, changing its XXXColor fields and then passing it to MarshalWithFormatter, MarshalIndentWithFormatter or NewEncoderWithFormatter. If a XXXColor field of the custom Formatter is not set, the corresponding DefaultXXXColor package variable is used. See color.New for creating custom color values and the GoDocs for the default colors.

import (
        "fmt"
        "log"

        "github.com/fatih/color"
        json "github.com/nwidger/jsoncolor"
)

// create custom formatter
f := json.NewFormatter()

// set custom colors
f.StringColor = color.New(color.FgBlack, color.Bold)
f.TrueColor = color.New(color.FgWhite, color.Bold)
f.FalseColor = color.New(color.FgRed)
f.NumberColor = color.New(color.FgWhite)
f.NullColor = color.New(color.FgWhite, color.Bold)

// marshal v with custom formatter,
// dst contains colorized output
dst, err := json.MarshalWithFormatter(v, f)
if err != nil {
        log.Fatal(err)
}

// print colorized output to stdout
fmt.Println(string(dst))