Gradient palette editor — #390875 to #5bc8c9

/* https://grabient.com/_gH3gFsgJ5gEogHHgGFgMKgG6gH8gIqgJsgKk?style=linearGradient&steps=7&angle=270 */

background: linear-gradient(270deg, #390875 0.000%, #6235a8 16.667%, #9e69d9 33.333%, #c79cfb 50.000%, #c4c1ff 66.667%, #97d1f2 83.333%, #5bc8c9 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_gH3gFsgJ5gEogHHgGFgMKgG6gH8gIqgJsgKk?style=linearGradient&steps=7&angle=270 -->
            <defs>
              <linearGradient id="gradient" x1="1.000" y1="0.500" x2="0.000" y2="0.500">
        <stop offset="0.000" stop-color="#390875" /><stop offset="0.167" stop-color="#6235a8" /><stop offset="0.333" stop-color="#9e69d9" /><stop offset="0.500" stop-color="#c79cfb" /><stop offset="0.667" stop-color="#c4c1ff" /><stop offset="0.833" stop-color="#97d1f2" /><stop offset="1.000" stop-color="#5bc8c9" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#390875", "#6235a8", "#9e69d9", "#c79cfb", "#c4c1ff", "#97d1f2", "#5bc8c9"]

// https://grabient.com/_gH3gFsgJ5gEogHHgGFgMKgG6gH8gIqgJsgKk?style=linearGradient&steps=7&angle=270
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 7.0;
const float ANGLE = 270.0;

vec3 palette(float t) {
    vec3 a = vec3(0.503, 0.364, 0.633);
    vec3 b = vec3(0.296, 0.455, 0.389);
    vec3 c = vec3(0.778, 0.442, 0.508);
    vec3 d = vec3(0.554, 0.620, 0.676);
    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);
}

[
  [0.503, 0.364, 0.633],
  [0.296, 0.455, 0.389],
  [0.778, 0.442, 0.508],
  [0.554, 0.620, 0.676]
]