Put this in .obsidian/snippets/catppucin-mocha.css and activate it from Appearance.
..theme-dark.minimal-catppuccin-dark {
--color-red-rgb: 243,139,168; /* Red */
--color-orange-rgb: 250,179,135; /* Peach */
--color-yellow-rgb: 249,226,175; /* Yellow */
--color-green-rgb: 166,227,161; /* Green */
--color-cyan-rgb: 148,226,213; /* Teal */
--color-blue-rgb: 137,180,250; /* Blue */
--color-purple-rgb: 203,166,247; /* Mauve */
--color-pink-rgb: 245,194,231; /* Pink */
--color-red: #f38ba8; /* Red */
--color-orange: #fab387; /* Peach */
--color-yellow: #f9e2af; /* Yellow */
--color-green: #a6e3a1; /* Green */
--color-cyan: #94e2d5; /* Teal */
--color-blue: #89b4fa; /* Blue */
--color-purple: #cba6f7; /* Mauve */
--color-pink: #f5c2e7; /* Pink */
}
.theme-light.minimal-catppuccin-light.minimal-light-contrast .titlebar,
.theme-light.minimal-catppuccin-light.minimal-light-contrast.minimal-status-off .status-bar,
.theme-light.minimal-catppuccin-light.minimal-light-contrast .workspace-drawer.mod-left,
.theme-light.minimal-catppuccin-light.minimal-light-contrast .mod-left-split,
.theme-light.minimal-catppuccin-light.minimal-light-contrast .workspace-ribbon.mod-left:not(.is-collapsed),
.theme-light.minimal-catppuccin-light.minimal-light-contrast .theme-dark,
.theme-dark.minimal-catppuccin-dark {
--base-h: 237; /* Surface0 */
--base-s: 16%; /* Surface0 */
--base-l: 23%; /* Surface0 */
--accent-h: 23; /* Peach */
--accent-s: 92%; /* Peach */
--accent-l: 75%; /* Peach */
--bg1: #1e1e2e; /* Base */
--bg2: #181825; /* Mantle */
--bg3: #313244; /* Surface0 */
--ui1: #45475a; /* Surface1 */
--ui2: #585b70; /* Surface2 */
--ui3: #6c7086; /* Overlay0 */
--tx1: #cdd6f4; /* Text */
--tx2: #a6adc8; /* Subtext0 */
--tx3: #9399b2; /* Overlay2 */
--sp1: #242634; /* Mantle */
--hl1: rgba(108, 112, 134, 0.4); /* Overlay0 */
--hl2: rgb(116, 199, 236, 0.2); /* Sapphire */
}