INTRODUCTION

The purpose of this chapter is to provide well-controlled methods for the assessment of color and achromicity of uniform liquid samples. The methods described in this chapter may be applied to the liquid phase of dispersed systems in cases where the dispersed phase can be removed prior to color measurements. Color is an organoleptic characteristic, which means that the value is based on the human response to stimuli. To reliably evaluate color, it is important to control both the illumination and observation parameters. By using a characteristic response for a standard observer, it is possible to perform precise instrumental evaluations of color. This chapter provides guidance for both an organoleptic assessment (Method I) and an instrumental assessment (Method II) of color and achromicity in liquid samples.