diff --git a/crates/core/models/src/v0/server_members.rs b/crates/core/models/src/v0/server_members.rs
index bcded0b0..d4559d2d 100644
--- a/crates/core/models/src/v0/server_members.rs
+++ b/crates/core/models/src/v0/server_members.rs
@@ -23,12 +23,13 @@ use rocket::FromForm;
 /// ```regex
 /// VALUE = [a-z ]+|var\(--[a-z\d-]+\)|rgba?\([\d, ]+\)|#[a-f0-9]+
 /// ADDITIONAL_VALUE = \d+deg
+/// COLOUR_SPACE = in [a-z-]+([ ]+(shorter|longer|increasing|decreasing)[ ]+hue)?
 /// STOP = ([ ]+(\d{1,3}%|0))?
 ///
-/// ^(?:VALUE|(repeating-)?(linear|conic|radial)-gradient\((VALUE|ADDITIONAL_VALUE)STOP(,[ ]*(VALUE)STOP)+\))$
+/// ^(?:VALUE|(repeating-)?(linear|conic|radial)-gradient\((VALUE|ADDITIONAL_VALUE)(COLOUR_SPACE)?STOP(,[ ]*(VALUE)STOP)+\))$
 /// ```
 pub static RE_COLOUR: Lazy<Regex> = Lazy::new(|| {
-    Regex::new(r"(?i)^(?:[a-z ]+|var\(--[a-z\d-]+\)|rgba?\([\d, ]+\)|#[a-f0-9]+|(repeating-)?(linear|conic|radial)-gradient\(([a-z ]+|var\(--[a-z\d-]+\)|rgba?\([\d, ]+\)|#[a-f0-9]+|\d+deg)([ ]+(\d{1,3}%|0))?(,[ ]*([a-z ]+|var\(--[a-z\d-]+\)|rgba?\([\d, ]+\)|#[a-f0-9]+)([ ]+(\d{1,3}%|0))?)+\))$").unwrap()
+    Regex::new(r"(?i)^(?:[a-z ]+|var\(--[a-z\d-]+\)|rgba?\([\d, ]+\)|#[a-f0-9]+|(repeating-)?(linear|conic|radial)-gradient\(([a-z ]+|var\(--[a-z\d-]+\)|rgba?\([\d, ]+\)|#[a-f0-9]+|\d+deg)([ ]+in[ ]+[a-z-]+([ ]+(shorter|longer|increasing|decreasing)[ ]+hue)?)?([ ]+(\d{1,3}%|0))?(,[ ]*([a-z ]+|var\(--[a-z\d-]+\)|rgba?\([\d, ]+\)|#[a-f0-9]+)([ ]+(\d{1,3}%|0))?)+\))$").unwrap()
 });
 
 fn default_true() -> bool {