/* https://grabient.com/_f8jgGff8dgRCgH3gTggDLgKngEkgACgPKgO2 */

background: linear-gradient(90deg, #dee8f5 0.000%, #d7d9ff 16.667%, #c394f6 33.333%, #a53bcc 50.000%, #7c008a 66.667%, #4c0035 83.333%, #151e00 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_f8jgGff8dgRCgH3gTggDLgKngEkgACgPKgO2 -->
            <defs>
              <linearGradient id="gradient" x1="0.000" y1="0.500" x2="1.000" y2="0.500">
        <stop offset="0.000" stop-color="#dee8f5" /><stop offset="0.167" stop-color="#d7d9ff" /><stop offset="0.333" stop-color="#c394f6" /><stop offset="0.500" stop-color="#a53bcc" /><stop offset="0.667" stop-color="#7c008a" /><stop offset="0.833" stop-color="#4c0035" /><stop offset="1.000" stop-color="#151e00" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#dee8f5", "#d7d9ff", "#c394f6", "#a53bcc", "#7c008a", "#4c0035", "#151e00"]

// https://grabient.com/_f8jgGff8dgRCgH3gTggDLgKngEkgACgPKgO2
// 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(-0.221, 0.415, -0.227);
    vec3 b = vec3(1.090, 0.503, 1.248);
    vec3 c = vec3(0.203, 0.679, 0.292);
    vec3 d = vec3(0.002, 0.970, 0.950);
    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);
}

[
  [-0.221, 0.415, -0.227],
  [1.090, 0.503, 1.248],
  [0.203, 0.679, 0.292],
  [0.002, 0.970, 0.950]
]

Gradient palette editor — #dee8f5 to #151e00