/* https://grabient.com/_hUagD1gEjhVMgDQgC1gBigNbgX6gHYgHdgFO?style=linearGradient&steps=7&angle=225 */

background: linear-gradient(225deg, #090a33 0.000%, #001823 16.667%, #004364 33.333%, #006b70 50.000%, #19712e 66.667%, #425126 83.333%, #782369 100.000%);

<svg xmlns="http://www.w3.org/2000/svg" width="800" height="400" viewBox="0 0 800 400" preserveAspectRatio="none">
            <!-- https://grabient.com/_hUagD1gEjhVMgDQgC1gBigNbgX6gHYgHdgFO?style=linearGradient&steps=7&angle=225 -->
            <defs>
              <linearGradient id="gradient" x1="0.854" y1="0.146" x2="0.146" y2="0.854">
        <stop offset="0.000" stop-color="#090a33" /><stop offset="0.167" stop-color="#001823" /><stop offset="0.333" stop-color="#004364" /><stop offset="0.500" stop-color="#006b70" /><stop offset="0.667" stop-color="#19712e" /><stop offset="0.833" stop-color="#425126" /><stop offset="1.000" stop-color="#782369" />
              </linearGradient>
            </defs>
            <rect x="0" y="0" width="800" height="400" fill="url(#gradient)" />
          </svg>

["#090a33", "#001823", "#004364", "#006b70", "#19712e", "#425126", "#782369"]

// https://grabient.com/_hUagD1gEjhVMgDQgC1gBigNbgX6gHYgHdgFO?style=linearGradient&steps=7&angle=225
// cosine gradient palette — https://iquilezles.org/articles/palettes/
const float STEPS = 7.0;
const float ANGLE = 225.0;

vec3 palette(float t) {
    vec3 a = vec3(5.402, 0.245, 0.291);
    vec3 b = vec3(5.452, 0.208, 0.181);
    vec3 c = vec3(0.098, 0.859, 1.530);
    vec3 d = vec3(0.472, 0.477, 0.334);
    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);
}

[
  [5.402, 0.245, 0.291],
  [5.452, 0.208, 0.181],
  [0.098, 0.859, 1.530],
  [0.472, 0.477, 0.334]
]

Gradient palette editor — #090a33 to #782369