Earthy rainbow marine blue to brownish red to light brown to gainsboro gradient palette editor

/* https://grabient.com/_fy2gIOgPFga2gFMgKagCzgJCgE-gNIgG5gGF */

background: linear-gradient(90deg, #143774 0.000%, #553457 16.667%, #8b4e4c 33.333%, #b57c54 50.000%, #d1ad6d 66.667%, #ded196 83.333%, #dcdac9 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_fy2gIOgPFga2gFMgKagCzgJCgE-gNIgG5gGF -->
            <defs>
              <linearGradient id="gradient" x1="0.000" y1="0.500" x2="1.000" y2="0.500">
        <stop offset="0.000" stop-color="#143774" /><stop offset="0.167" stop-color="#553457" /><stop offset="0.333" stop-color="#8b4e4c" /><stop offset="0.500" stop-color="#b57c54" /><stop offset="0.667" stop-color="#d1ad6d" /><stop offset="0.833" stop-color="#ded196" /><stop offset="1.000" stop-color="#dcdac9" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#143774", "#553457", "#8b4e4c", "#b57c54", "#d1ad6d", "#ded196", "#dcdac9"]

// https://grabient.com/_fy2gIOgPFga2gFMgKagCzgJCgE-gNIgG5gGF
// 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(-0.842, 0.526, 0.965);
    vec3 b = vec3(1.718, 0.332, 0.666);
    vec3 c = vec3(0.179, 0.578, 0.318);
    vec3 d = vec3(0.840, 0.441, 0.389);
    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);
}

[
  [-0.842, 0.526, 0.965],
  [1.718, 0.332, 0.666],
  [0.179, 0.578, 0.318],
  [0.840, 0.441, 0.389]
]