Rainbow dark brown to burgundy to dark gray blue to green brown gradient palette editor

/* https://grabient.com/_gDkgDIgDTgBNgCmgC8gVngMogPlgI8gFRgGn?style=linearGradient&steps=8&angle=315 */

background: linear-gradient(315deg, #281d0b 0.000%, #3d0b0a 14.286%, #4d0c29 28.571%, #442252 42.857%, #2d4066 57.143%, #285755 71.429%, #3b5d2e 85.714%, #4d4d0c 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_gDkgDIgDTgBNgCmgC8gVngMogPlgI8gFRgGn?style=linearGradient&steps=8&angle=315 -->
            <defs>
              <linearGradient id="gradient" x1="0.854" y1="0.854" x2="0.146" y2="0.146">
        <stop offset="0.000" stop-color="#281d0b" /><stop offset="0.143" stop-color="#3d0b0a" /><stop offset="0.286" stop-color="#4d0c29" /><stop offset="0.429" stop-color="#442252" /><stop offset="0.571" stop-color="#2d4066" /><stop offset="0.714" stop-color="#285755" /><stop offset="0.857" stop-color="#3b5d2e" /><stop offset="1.000" stop-color="#4d4d0c" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#281d0b", "#3d0b0a", "#4d0c29", "#442252", "#2d4066", "#285755", "#3b5d2e", "#4d4d0c"]

// https://grabient.com/_gDkgDIgDTgBNgCmgC8gVngMogPlgI8gFRgGn?style=linearGradient&steps=8&angle=315
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 8.0;
const float ANGLE = 315.0;

vec3 palette(float t) {
    vec3 a = vec3(0.228, 0.200, 0.211);
    vec3 b = vec3(0.077, 0.166, 0.188);
    vec3 c = vec3(1.383, 0.808, 0.997);
    vec3 d = vec3(0.572, 0.337, 0.423);
    return a + b * cos(6.283185 * (c * t + d));
}

// N stops sampled from the palette, blended like the CSS gradient
vec3 stops(float t) {
    float n = STEPS - 1.0;
    float x = clamp(t, 0.0, 1.0) * n;
    return mix(palette(floor(x) / n), palette(min(floor(x) + 1.0, n) / n), fract(x));
}

void mainImage(out vec4 fragColor, in vec2 fragCoord) {
    vec2 p = fragCoord - 0.5 * iResolution.xy;
    // CSS angle: 0 = up, clockwise; span = CSS gradient-line length
    vec2 dir = vec2(sin(radians(ANGLE)), cos(radians(ANGLE)));
    float len = abs(iResolution.x * dir.x) + abs(iResolution.y * dir.y);
    float t = dot(p, dir) / len + 0.5;
    fragColor = vec4(stops(t), 1.0);
}

[
  [0.228, 0.200, 0.211],
  [0.077, 0.166, 0.188],
  [1.383, 0.808, 0.997],
  [0.572, 0.337, 0.423]
]