Muted monochrome charcoal to light periwinkle gradient palette editor

/* https://grabient.com/_gSDgT9gJzgRLgRFgGRgBjgBngE2gJTgI5gJb */

background: linear-gradient(90deg, #3f494e 0.000%, #505766 16.667%, #646884 33.333%, #7a7ba5 50.000%, #9291c5 66.667%, #aba9e2 83.333%, #c6c2f7 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_gSDgT9gJzgRLgRFgGRgBjgBngE2gJTgI5gJb -->
            <defs>
              <linearGradient id="gradient" x1="0.000" y1="0.500" x2="1.000" y2="0.500">
        <stop offset="0.000" stop-color="#3f494e" /><stop offset="0.167" stop-color="#505766" /><stop offset="0.333" stop-color="#646884" /><stop offset="0.500" stop-color="#7a7ba5" /><stop offset="0.667" stop-color="#9291c5" /><stop offset="0.833" stop-color="#aba9e2" /><stop offset="1.000" stop-color="#c6c2f7" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#3f494e", "#505766", "#646884", "#7a7ba5", "#9291c5", "#aba9e2", "#c6c2f7"]

// https://grabient.com/_gSDgT9gJzgRLgRFgGRgBjgBngE2gJTgI5gJb
// 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(1.155, 1.277, 0.627);
    vec3 b = vec3(1.099, 1.093, 0.401);
    vec3 c = vec3(0.099, 0.103, 0.310);
    vec3 d = vec3(0.595, 0.569, 0.603);
    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);
}

[
  [1.155, 1.277, 0.627],
  [1.099, 1.093, 0.401],
  [0.099, 0.103, 0.310],
  [0.595, 0.569, 0.603]
]