Gradient palette editor — #257d6d to #137fc8

/* https://grabient.com/_gIbgKUgHWgHggCqgGogQegQngJpgGTgHogEK?style=linearGradient&steps=8&angle=270 */

background: linear-gradient(270deg, #257d6d 0.000%, #168d36 14.286%, #67b413 28.571%, #d4d10e 42.857%, #ffcc28 57.143%, #cea95b 71.429%, #5f8596 85.714%, #137fc8 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_gIbgKUgHWgHggCqgGogQegQngJpgGTgHogEK?style=linearGradient&steps=8&angle=270 -->
            <defs>
              <linearGradient id="gradient" x1="1.000" y1="0.500" x2="0.000" y2="0.500">
        <stop offset="0.000" stop-color="#257d6d" /><stop offset="0.143" stop-color="#168d36" /><stop offset="0.286" stop-color="#67b413" /><stop offset="0.429" stop-color="#d4d10e" /><stop offset="0.571" stop-color="#ffcc28" /><stop offset="0.714" stop-color="#cea95b" /><stop offset="0.857" stop-color="#5f8596" /><stop offset="1.000" stop-color="#137fc8" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#257d6d", "#168d36", "#67b413", "#d4d10e", "#ffcc28", "#cea95b", "#5f8596", "#137fc8"]

// https://grabient.com/_gIbgKUgHWgHggCqgGogQegQngJpgGTgHogEK?style=linearGradient&steps=8&angle=270
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 8.0;
const float ANGLE = 270.0;

vec3 palette(float t) {
    vec3 a = vec3(0.539, 0.660, 0.470);
    vec3 b = vec3(0.480, 0.170, 0.424);
    vec3 c = vec3(1.054, 1.063, 0.617);
    vec3 d = vec3(0.403, 0.488, 0.266);
    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);
}

[
  [0.539, 0.660, 0.470],
  [0.480, 0.170, 0.424],
  [1.054, 1.063, 0.617],
  [0.403, 0.488, 0.266]
]