/* https://grabient.com/_guDiLfgfugrziMUgfkgBngBkgBhgH2gHXgIq?style=linearGradient&steps=5&angle=135 */

background: linear-gradient(135deg, #251820 0.000%, #300040 25.000%, #4d066a 50.000%, #7c519d 75.000%, #bbd3da 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_guDiLfgfugrziMUgfkgBngBkgBhgH2gHXgIq?style=linearGradient&steps=5&angle=135 -->
            <defs>
              <linearGradient id="gradient" x1="0.146" y1="0.146" x2="0.854" y2="0.854">
        <stop offset="0.000" stop-color="#251820" /><stop offset="0.250" stop-color="#300040" /><stop offset="0.500" stop-color="#4d066a" /><stop offset="0.750" stop-color="#7c519d" /><stop offset="1.000" stop-color="#bbd3da" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#251820", "#300040", "#4d066a", "#7c519d", "#bbd3da"]

// https://grabient.com/_guDiLfgfugrziMUgfkgBngBkgBhgH2gHXgIq?style=linearGradient&steps=5&angle=135
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 5.0;
const float ANGLE = 135.0;

vec3 palette(float t) {
    vec3 a = vec3(2.947, 8.927, 2.030);
    vec3 b = vec3(2.803, 8.980, 2.020);
    vec3 c = vec3(0.103, 0.100, 0.097);
    vec3 d = vec3(0.502, 0.471, 0.554);
    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);
}

[
  [2.947, 8.927, 2.030],
  [2.803, 8.980, 2.020],
  [0.103, 0.100, 0.097],
  [0.502, 0.471, 0.554]
]

Gradient palette editor — #251820 to #bbd3da