The problem with ColorNameFinder's algorithm

[pentiumao]

I found one problem when I name the color of #444444.
"mine_shaft" was given by plugin, the same as the color of #222222, but they are a little bit different.
Then I input #444444 on the website name that color, but I got the name of "Tundora".

Steps to reproduce:

println(ColorNameFinder.findColor(HexColor("#444444")))

Actual result:

(#444444, Color(hexCode=323232, name=Mine Shaft, rgb=Rgb(r=50, g=50, b=50), hsl=Hsl(h=0, s=0, l=20)))

Expected result:

(#444444, Color(hexCode=4A4244, name=Tundora, rgb=Rgb(r=74, g=66, b=68), hsl=Hsl(h=345, s=6, l=27)))

I think the problem is at this line after I checked the source of ntc:

name-that-color-intellij-plugin/namethatcolor/src/main/kotlin/il/co/galex/namethatcolor/core/manager/ColorNameFinder.kt

Line 46 in 69d18a1

val ndf2 = Math.pow((h - col.hsl.h).toDouble(), 2.0).toInt() + Math.pow((s - col.hsl.s).toDouble(), 2.0).toInt() + Math.pow((l - col.hsl.l).toDouble(), 2.0).toInt()

Let's look at the HSL value of three colors:

#4A4244  Rgb(r=74, g=66, b=68) Hsl(h=345, s=6, l=27)
#323232  Rgb(r=50, g=50, b=50) Hsl(h=0, s=0, l=20)
#444444  Rgb(r=68, g=68, b=68) Hsl(h=0, s=0, l=27)

Because H in HSL represents a degree, the delta value between #4A4244 and #444444 should be 15 but not 345. As a result, it makes #323232 be the closest color to #444444.

The fix should be something like this:

private fun deltaOfTwoDegree(l: Int, r: Int): Int {
    var delta = abs(l - r)
    if (delta >= 180) {
        delta = (360 - delta)
    }
    return delta
}

Hope it helps.