Gradient palette editor — #583300 to #707a55

/* https://grabient.com/_gGJgFIfu6gBigCYgXPgH2gGUgBlgKcgJLgNW */

background: linear-gradient(90deg, #583300 0.000%, #643e00 16.667%, #714d0a 33.333%, #7a5d22 50.000%, #7d6c37 66.667%, #7a7648 83.333%, #707a55 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_gGJgFIfu6gBigCYgXPgH2gGUgBlgKcgJLgNW -->
            <defs>
              <linearGradient id="gradient" x1="0.000" y1="0.500" x2="1.000" y2="0.500">
        <stop offset="0.000" stop-color="#583300" /><stop offset="0.167" stop-color="#643e00" /><stop offset="0.333" stop-color="#714d0a" /><stop offset="0.500" stop-color="#7a5d22" /><stop offset="0.667" stop-color="#7d6c37" /><stop offset="0.833" stop-color="#7a7648" /><stop offset="1.000" stop-color="#707a55" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#583300", "#643e00", "#714d0a", "#7a5d22", "#7d6c37", "#7a7648", "#707a55"]

// https://grabient.com/_gGJgFIfu6gBigCYgXPgH2gGUgBlgKcgJLgNW
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 7.0;
const float ANGLE = 90.0;

vec3 palette(float t) {
    vec3 a = vec3(0.393, 0.328, -1.094);
    vec3 b = vec3(0.098, 0.152, 1.487);
    vec3 c = vec3(0.502, 0.404, 0.101);
    vec3 d = vec3(0.668, 0.587, 0.854);
    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);
}

[
  [0.393, 0.328, -1.094],
  [0.098, 0.152, 1.487],
  [0.502, 0.404, 0.101],
  [0.668, 0.587, 0.854]
]