Sunset duotone maroon and bluegray gradient palette editor

/* https://grabient.com/_fSVgGKgmJg4AgG9gl8gBigEOgBggO4gJDgIT?style=linearGradient&steps=6&angle=270 */

background: linear-gradient(270deg, #7f010f 0.000%, #9a1822 20.000%, #a7393d 40.000%, #a65e61 60.000%, #98848c 80.000%, #7ca7be 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_fSVgGKgmJg4AgG9gl8gBigEOgBggO4gJDgIT?style=linearGradient&steps=6&angle=270 -->
            <defs>
              <linearGradient id="gradient" x1="1.000" y1="0.500" x2="0.000" y2="0.500">
        <stop offset="0.000" stop-color="#7f010f" /><stop offset="0.200" stop-color="#9a1822" /><stop offset="0.400" stop-color="#a7393d" /><stop offset="0.600" stop-color="#a65e61" /><stop offset="0.800" stop-color="#98848c" /><stop offset="1.000" stop-color="#7ca7be" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#7f010f", "#9a1822", "#a7393d", "#a65e61", "#98848c", "#7ca7be"]

// https://grabient.com/_fSVgGKgmJg4AgG9gl8gBigEOgBggO4gJDgIT?style=linearGradient&steps=6&angle=270
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 6.0;
const float ANGLE = 270.0;

vec3 palette(float t) {
    vec3 a = vec3(-2.923, 0.394, 2.441);
    vec3 b = vec3(3.584, 0.445, 2.428);
    vec3 c = vec3(0.098, 0.270, 0.096);
    vec3 d = vec3(0.952, 0.579, 0.531);
    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);
}

[
  [-2.923, 0.394, 2.441],
  [3.584, 0.445, 2.428],
  [0.098, 0.270, 0.096],
  [0.952, 0.579, 0.531]
]