function createColorElement(colorStr, innerElements) {
		var isHexaRgb = REGEX_HEX_COLOR.test(colorStr);
		if ( !isHexaRgb && SCHEME_COLOR_NAMES.indexOf(colorStr) === -1 ) {
			console.warn('"' + colorStr + '" is not a valid scheme color or hexa RGB! "'+DEF_FONT_COLOR+'" is used as a fallback. Pass 6-digit RGB or these `pptx.colors` values:\n' + SCHEME_COLOR_NAMES.join(', '));
			colorStr = DEF_FONT_COLOR;
		}
		var tagName = isHexaRgb ? 'srgbClr' : 'schemeClr';
		var colorAttr = ' val="'+ colorStr +'"';
		return innerElements ? '<a:'+ tagName + colorAttr +'>'+ innerElements +'</a:'+ tagName +'>' : '<a:'+ tagName + colorAttr +' />';
	}
DESC: Depending on the passed color string, creates either `a:schemeClr` (when scheme color) or `a:srgbClr` (when hexa representation).
color (string): hexa representation (eg. "FFFF00") or a scheme color constant (eg. colors.ACCENT1)
innerElements (optional string): Additional elements that adjust the color and are enclosed by the color element.