Fitness to Work Assessment for Oil Palm Fruits Harvest Workers Diagnosed with Color Blindness using Color Blind Test Media Based on the Color of Oil Palm Fruit : Indian Journal of Occupational and Environmental Medicine

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Fitness to Work Assessment for Oil Palm Fruits Harvest Workers Diagnosed with Color Blindness using Color Blind Test Media Based on the Color of Oil Palm Fruit

Kramy, Prayogi; Kuswadji, Sudjoko1

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Indian Journal of Occupational and Environmental Medicine 27(1):p 84-88, Jan–Mar 2023. | DOI: 10.4103/ijoem.ijoem_147_22
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Color blindness can impede a person's ability to work or engage in color-related activities. In some countries, a person with color blindness is prohibited from possessing a driver's license due to their inability to discriminate between the colors of traffic signals.[12] Another example is a pilot whose profession demands color perception in multiple capacities.[3] Approximately, eight percent of males and females worldwide are color blind. Approximately 0.5 percent in women, with a male-to-female ratio of 1:12 to 1:200.[45] Color vision deficiency (CVD) or color blindness can be classified in several forms, such as anomalous trichromacy, dichromacy, and monochromacy.[678]

Indonesia is one of the world's top producers of palm oil, employing up to 6.86 million people.[9] Work in the palm oil business demands the capacity to see color in certain circumstances, particularly for oil palm fruit harvest workers and fruits grading officer who judge the quality of palm fruit ripeness.[10] When doing a Medical Check-Up (MCU) for workers, doctors typically administer a color blindness test whose results have a substantial impact on whether or not a potential worker is fit for work.

Generally, doctors assess for color blindness using the Ishihara test, but this test lacks a gradation to identify the degree of color blindness[11] making it difficult for a physician to determine whether a potential oil palm harvest workers is fit for work. Due to the conclusions of the MCU, possible color blind oil palm fruits harvest workers may lose their jobs as a result. The Hardy-Rand-Rittler (HRR) test, which can grade the severity of color blindness, is another possible test for detecting color blindness; however, this test is rarely administered in Indonesia due to the limited availability and circulation of test materials.[12] It should be realized that not all oil palm fruits harvest workers with direct color blindness are unfit for work because the severity of the type of color blindness encountered must be evaluated further. There are also discrepancies in the sorts or varieties of oil palm fruit farmed by enterprises in the palm oil industry, resulting in differing perceptions of color and maturity level; hence, there is no standard or reference for assessing the color of the ripe oil palm fruits. In the lack of a practical test method to determine the eligibility of a color blind oil palm fruits harvester, a simple yet effective test that can be modified for each enterprise is required.


In harvesting oil palm fruit, the ability to distinguish between ripe and unripe fruit is required. Generally, ripe oil palm fruits will be yellowish-red, but please note, that the types of oil palm fruit planted by companies in the oil palm industry have different varieties, so the determination of the color of fruit maturity also has differences. Based on the color of the fruit, oil palms can be classified into Nigrescens, Virescens, and Albescens.[13] Fruits with the Nigrescens variety are the most common oil palm fruits in Indonesia. Nigrescens have a violet to black color when unripe and turn yellowish-red (orange) when ripe as shown in Figure 1.[14] As seen in Figure 2, the Virescens variety has a green color when unripe and turns red-yellow (orange) when ripe.[15] Virescent oil palm fruit is rarely found in the field. Albescent oil palm fruit has an ashen yellowish color at the base of the young fruit, while the ripe fruit has a dark yellow color, and the tip of the fruit has a purple-black color as shown in Figure 3.[15] Albescent-type fruit is very rarely found in the field.

Figure 1:
Figure 2:
Figure 3:

To Assessing the fitness to work of color blind oil palm fruit harvest workers, a simple tool was made by taking samples of the ripe and unripe palm fruit. The fruit is then photographed with a smartphone camera and then the colors from the photos are extracted using the Adobe Color application as shown in Figures 4 and 5.[16]

Figure 4:
Color extraction of ripe oil palm fruit
Figure 5:
Color extraction of unripe palm fruit

The color extraction of ripe palm fruit is obtained in the form of a HEX (hexadecimal) code that follows the basic color format #RRGGBB, where RR is Red (Red), GG is Green (Green), and BB is Blue (Blue).[16] The color extraction results are then arranged randomly as shown in Figure 6.

Figure 6:
Color extraction results of ripe and unripe oil palm fruits


The color extraction of ripe and unripe palm fruit arranged randomly is made side-by-side between the color of the unripe and ripe fruit, as shown in Figure 6. In color numbers 1 to 12, there is a possibility that people with dichromatic and monochromatic color blindness can still recognize the color of the fruit. But in numbers 13 to 18, dichromatic and monochromatic color blind people will have difficulty recognizing the color of ripe fruit and unripe fruit because of the similarity in color resulting from visual defects in color blindness.[17] To make it easier to understand, through an application to simulate color blindness, a visual picture of color blind people can be made on the test media (tools) that have been made previously.[1819] People with dichromatic color blindness, especially in protanopia, will find it challenging to distinguish ripe palm fruit and unripe palm fruit due to visual defects in red-green color as shown in Figures 7 and 8.[18] If someone with CVD could identify the color of ripe and unripe oil palm fruits based on Figure 6, this shows the severity of the color blindness suffered is not severe. Trichromatic or anomalous trichromacy is the most common color blindness type in the world. Someone with this type of CVD is still able to recognize colors, even though they have difficulty recognizing some colors. However, it should be noted that Virescens palm fruit when unripe will be green, making it difficult for people with green color blindness (deuteranomaly) to recognize it. Oil palm fruit harvesters with deuteranomalies are still possible to work but with a note that they can only harvest in oil palm plantation areas with Nigrescens and Albescens species. With normal physical examination results and recognizing ripe fruit and unripe fruit, oil palm fruit harvest workers can already be declared fit for work.

Figure 7:
C (common) colors seen by normal people; P (Protanomaly); D (Deuteranomaly); T (Tritanomaly)
Figure 8:
C (common) colors seen by normal people; P (Protanopia); D (Deuteranopia); T (Tritanopia)


Further studies in the form of sensitivity and specificity tests are required to determine the efficacy of this test so that it may be utilized as a standard for determining the job eligibility of palm oil fruit harvesters with color blindness. It should be underlined that this test can only be used in the palm oil industry.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


The author would like to express special thanks to Public Health Faculty of Hasanuddin University and Mrs. Eya Nadia for advice and inspiration to write this article.


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Color blindness; color blind test; fitness to work; oil palm fruits color

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