curl --request PUT \
  --url https://api.loyalty.dog/v2/giftcards/merchants/theme \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "presetId": "eposn-default",
  "primary": "#15803d",
  "primaryFg": "#ffffff",
  "sidebarBg": "#ffffff",
  "sidebarText": "#4b5563",
  "sidebarActiveBg": "#f0fdf4",
  "sidebarActiveText": "#15803d",
  "sidebarBadge": "#15803d",
  "background": "#f9fafb",
  "foreground": "#111827",
  "surface": "#ffffff",
  "border": "#e5e7eb",
  "muted": "#6b7280",
  "logoUrl": "<string>",
  "logoAlt": "<string>",
  "fontFamily": "<string>",
  "borderRadius": "lg"
}
'

{
  "theme": {
    "presetId": "eposn-default",
    "primary": "#15803d",
    "primaryFg": "#ffffff",
    "sidebarBg": "#ffffff",
    "sidebarText": "#4b5563",
    "sidebarActiveBg": "#f0fdf4",
    "sidebarActiveText": "#15803d",
    "sidebarBadge": "#15803d",
    "background": "#f9fafb",
    "foreground": "#111827",
    "surface": "#ffffff",
    "border": "#e5e7eb",
    "muted": "#6b7280",
    "logoUrl": "<string>",
    "logoAlt": "<string>",
    "fontFamily": "<string>",
    "borderRadius": "lg"
  },
  "validation": {},
  "performance": {
    "cssVarChanges": 123,
    "hasCustomFont": true,
    "hasLargeLogo": true,
    "issues": [
      {
        "severity": "<string>",
        "code": "<string>",
        "message": "<string>",
        "estimatedMs": 123
      }
    ],
    "score": 123
  }
}