/* https://grabient.com/_gG6gFQgHKgKGgFOgHVgJAgIpgMVgM_gA2gGu?style=linearGradient&steps=7&angle=180 */

background: linear-gradient(180deg, #c1a609 0.000%, #ff8906 16.667%, #ff5c4b 33.333%, #e92cab 50.000%, #950ae8 66.667%, #3301db 83.333%, #00138c 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_gG6gFQgHKgKGgFOgHVgJAgIpgMVgM_gA2gGu?style=linearGradient&steps=7&angle=180 -->
            <defs>
              <linearGradient id="gradient" x1="0.500" y1="0.000" x2="0.500" y2="1.000">
        <stop offset="0.000" stop-color="#c1a609" /><stop offset="0.167" stop-color="#ff8906" /><stop offset="0.333" stop-color="#ff5c4b" /><stop offset="0.500" stop-color="#e92cab" /><stop offset="0.667" stop-color="#950ae8" /><stop offset="0.833" stop-color="#3301db" /><stop offset="1.000" stop-color="#00138c" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#c1a609", "#ff8906", "#ff5c4b", "#e92cab", "#950ae8", "#3301db", "#00138c"]

// https://grabient.com/_gG6gFQgHKgKGgFOgHVgJAgIpgMVgM_gA2gGu?style=linearGradient&steps=7&angle=180
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 7.0;
const float ANGLE = 180.0;

vec3 palette(float t) {
    vec3 a = vec3(0.442, 0.336, 0.458);
    vec3 b = vec3(0.646, 0.334, 0.469);
    vec3 c = vec3(0.576, 0.553, 0.789);
    vec3 d = vec3(0.831, 0.054, 0.430);
    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);
}

[
  [0.442, 0.336, 0.458],
  [0.646, 0.334, 0.469],
  [0.576, 0.553, 0.789],
  [0.831, 0.054, 0.430]
]

Gradient palette editor — #c1a609 to #00138c