Gradient palette editor — #12003a to #c8bce5

/* https://grabient.com/_gLBezRgIzgKMhZFgFngEzgBjgHzgHOgNvgIw?style=linearGradient&steps=6&angle=225 */

background: linear-gradient(225deg, #12003a 0.000%, #0f005e 20.000%, #250f95 40.000%, #4f5eca 60.000%, #8898e8 80.000%, #c8bce5 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_gLBezRgIzgKMhZFgFngEzgBjgHzgHOgNvgIw?style=linearGradient&steps=6&angle=225 -->
            <defs>
              <linearGradient id="gradient" x1="0.854" y1="0.146" x2="0.146" y2="0.854">
        <stop offset="0.000" stop-color="#12003a" /><stop offset="0.200" stop-color="#0f005e" /><stop offset="0.400" stop-color="#250f95" /><stop offset="0.600" stop-color="#4f5eca" /><stop offset="0.800" stop-color="#8898e8" /><stop offset="1.000" stop-color="#c8bce5" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#12003a", "#0f005e", "#250f95", "#4f5eca", "#8898e8", "#c8bce5"]

// https://grabient.com/_gLBezRgIzgKMhZFgFngEzgBjgHzgHOgNvgIw?style=linearGradient&steps=6&angle=225
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 6.0;
const float ANGLE = 225.0;

vec3 palette(float t) {
    vec3 a = vec3(0.705, -4.911, 0.563);
    vec3 b = vec3(0.652, 5.701, 0.359);
    vec3 c = vec3(0.307, 0.099, 0.499);
    vec3 d = vec3(0.462, 0.879, 0.560);
    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);
}

[
  [0.705, -4.911, 0.563],
  [0.652, 5.701, 0.359],
  [0.307, 0.099, 0.499],
  [0.462, 0.879, 0.560]
]