{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T17:06:36Z","timestamp":1776963996439,"version":"3.51.4"},"reference-count":113,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2021,10,16]],"date-time":"2021-10-16T00:00:00Z","timestamp":1634342400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100008561","name":"Universiti Tenaga Nasional","doi-asserted-by":"publisher","award":["J5100D4103"],"award-info":[{"award-number":["J5100D4103"]}],"id":[{"id":"10.13039\/501100008561","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008561","name":"Universiti Tenaga Nasional","doi-asserted-by":"publisher","award":["RJO10517844\/054"],"award-info":[{"award-number":["RJO10517844\/054"]}],"id":[{"id":"10.13039\/501100008561","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>For most natural or naturally-derived liquid products, their color reflects on their quality and occasionally affects customer preferences. To date, there are a few subjective and objective methods for color measurement which are currently utilized by various industries. Researchers are also improving these methods and inventing new methods, as color is proven to have the ability to provide various information on the condition and quality of the liquid. However, a review on the methods, especially for amber-colored liquid, has not been conducted yet. This paper presents a comprehensive review on the subjective and objective methods for color measurement of amber-colored liquids. The pros and cons of the measurement methods, the effects of the color on customer preferences, and the international industry standards on color measurements are reviewed and discussed. In addition, this study elaborates on the issues and challenges related to the color measurement techniques as well as recommendations for future research. This review demonstrates that the existing color measurement technique can determine the color according to the standards and color scales. However, the efforts toward minimizing the complexity of the hardware while maximizing the signal processing through advanced computation are still lacking. Therefore, through this critical review, this review can hopefully intensify the efforts toward finding an optimized method or technique for color measurement of liquids and thus expedite the development of a portable device that can measure color accurately.<\/jats:p>","DOI":"10.3390\/s21206866","type":"journal-article","created":{"date-parts":[[2021,10,17]],"date-time":"2021-10-17T23:25:15Z","timestamp":1634513115000},"page":"6866","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":22,"title":["The Amber-Colored Liquid: A Review on the Color Standards, Methods of Detection, Issues and Recommendations"],"prefix":"10.3390","volume":"21","author":[{"given":"Muhamad Haziq","family":"Hasnul Hadi","sequence":"first","affiliation":[{"name":"Institute of Sustainable Energy, Universiti Tenaga Nasional, Kajang 43000, Malaysia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5703-1735","authenticated-orcid":false,"given":"Pin Jern","family":"Ker","sequence":"additional","affiliation":[{"name":"Institute of Sustainable Energy, Universiti Tenaga Nasional, Kajang 43000, Malaysia"}]},{"given":"Vimal A.","family":"Thiviyanathan","sequence":"additional","affiliation":[{"name":"Institute of Sustainable Energy, Universiti Tenaga Nasional, Kajang 43000, Malaysia"}]},{"given":"Shirley Gee Hoon","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Faculty of Medicine, Manipal University College Malaysia, Bukit Baru, Melaka 75150, Malaysia"},{"name":"International Medical School, Management and Science University, Shah Alam 40100, Malaysia"}]},{"given":"Yang Sing","family":"Leong","sequence":"additional","affiliation":[{"name":"Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environmental, Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Malaysia"}]},{"given":"Hui Jing","family":"Lee","sequence":"additional","affiliation":[{"name":"Institute of Power Engineering, Universiti Tenaga Nasional, Kajang 43000, Malaysia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8367-4112","authenticated-orcid":false,"given":"Mahammad A.","family":"Hannan","sequence":"additional","affiliation":[{"name":"Institute of Sustainable Energy, Universiti Tenaga Nasional, Kajang 43000, Malaysia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9637-6867","authenticated-orcid":false,"given":"Md. Zaini","family":"Jamaludin","sequence":"additional","affiliation":[{"name":"Institute of Power Engineering, Universiti Tenaga Nasional, Kajang 43000, Malaysia"}]},{"given":"Mohd Adzir","family":"Mahdi","sequence":"additional","affiliation":[{"name":"Wireless and Photonics Networks Research Centre, Faculty of Engineering, Universiti Putra Malaysia (UPM), Serdang 43400, Malaysia"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Berns, R.S. (2019). Billmeyer and Saltzman\u2019s Principles of Color Technology, John Wiley & Sons.","DOI":"10.1002\/9781119367314"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Fairchild, M.D. (2013). Color Appearance Models, John Wiley & Sons. [2nd ed.].","DOI":"10.1002\/9781118653128"},{"key":"ref_3","unstructured":"Tintometer Group (2013). 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