Dark duotone aubergine and yellowish brown gradient palette editor

/* https://grabient.com/_gvegESgDwgsDgDqgBTgBkgGHgPygHlgIOgE9?style=linearGradient&steps=6&angle=315 */

background: linear-gradient(315deg, #3b0b35 0.000%, #381728 20.000%, #412d39 40.000%, #544a50 60.000%, #73654c 80.000%, #9c7a33 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_gvegESgDwgsDgDqgBTgBkgGHgPygHlgIOgE9?style=linearGradient&steps=6&angle=315 -->
            <defs>
              <linearGradient id="gradient" x1="0.854" y1="0.854" x2="0.146" y2="0.146">
        <stop offset="0.000" stop-color="#3b0b35" /><stop offset="0.200" stop-color="#381728" /><stop offset="0.400" stop-color="#412d39" /><stop offset="0.600" stop-color="#544a50" /><stop offset="0.800" stop-color="#73654c" /><stop offset="1.000" stop-color="#9c7a33" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#3b0b35", "#381728", "#412d39", "#544a50", "#73654c", "#9c7a33"]

// https://grabient.com/_gvegESgDwgsDgDqgBTgBkgGHgPygHlgIOgE9?style=linearGradient&steps=6&angle=315
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 6.0;
const float ANGLE = 315.0;

vec3 palette(float t) {
    vec3 a = vec3(3.038, 0.274, 0.240);
    vec3 b = vec3(2.819, 0.234, 0.083);
    vec3 c = vec3(0.100, 0.391, 1.010);
    vec3 d = vec3(0.485, 0.526, 0.317);
    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);
}

[
  [3.038, 0.274, 0.240],
  [2.819, 0.234, 0.083],
  [0.100, 0.391, 1.010],
  [0.485, 0.526, 0.317]
]