glg.go
func (g *Glg) DisableLevelColor(lv LEVEL) *Glg {
	ins, ok := g.logger.Load(lv)
	if ok {
		l := ins.(*logger)
		l.isColor = false
		l.updateMode()
		g.logger.Store(lv, l)
	}
	return g
}
func (g *Glg) DisableLevelColor(lv LEVEL) *Glg {
	ins, ok := g.logger.Load(lv)
	if ok {
		l := ins.(*logger)
		l.isColor = false
		l.updateMode()
		g.logger.Store(lv, l)
	}
	return g
}
// DisableLevelColor disables color output