Refine the color algorithm to make it align with Liquid Glass better

Author: TimOliver

TORoundedButton/TORoundedButton.h

@@ -116,7 +116,7 @@ IB_DESIGNABLE @interface TORoundedButton : UIControl
 @property (nonatomic, assign) IBInspectable CGFloat tappedTextAlpha;
 
 /// Taking the default button background color apply a brightness offset for the tapped color 
-/// (Default is -0.1f. Set 0.0 for off).
+/// (Default is 0.25f. Set 0.0 for off).
 @property (nonatomic, assign) IBInspectable CGFloat tappedTintColorBrightnessOffset;
 
 /// If desired, explicity set the background color of the button when tapped (Default is nil).

TORoundedButton/TORoundedButton.m

@@ -118,7 +118,7 @@ - (void)_roundedButtonCommonInit TOROUNDEDBUTTON_OBJC_DIRECT {
     _tappedTextAlpha = (_tappedTextAlpha > FLT_EPSILON) ?: 1.0f;
     _tapAnimationDuration = (_tapAnimationDuration > FLT_EPSILON) ?: 0.4f;
     _tappedButtonScale = (_tappedButtonScale > FLT_EPSILON) ?: 0.97f;
-    _tappedTintColorBrightnessOffset = !TORoundedButtonFloatIsZero(_tappedTintColorBrightnessOffset) ?: -0.15f;
+    _tappedTintColorBrightnessOffset = !TORoundedButtonFloatIsZero(_tappedTintColorBrightnessOffset) ?: 0.25f;
     _contentInset = (UIEdgeInsets){15.0, 15.0, 15.0, 15.0};
     _blurStyle = UIBlurEffectStyleDark;
     _impactStyle = TORoundedButtonImpactStyleMedium;
@@ -669,13 +669,65 @@ - (UIColor *)_labelBackgroundColor TOROUNDEDBUTTON_OBJC_DIRECT {
 }
 
 - (UIColor *)_brightnessAdjustedColorWithColor:(UIColor *)color amount:(CGFloat)amount TOROUNDEDBUTTON_OBJC_DIRECT {
-    if (!color) { return nil; }
+    // Clamp
+    amount = fmaxf(0.0, fminf(amount, 1.0));
 
-    CGFloat h, s, b, a;
-    if (![color getHue:&h saturation:&s brightness:&b alpha:&a]) { return nil; }
-    b += amount;
-    b = MAX(b, 0.0f); b = MIN(b, 1.0f);
-    return [UIColor colorWithHue:h saturation:s brightness:b alpha:a];
+    CGFloat h = 0, s = 0, b = 0, a = 0;
+    if (![color getHue:&h saturation:&s brightness:&b alpha:&a]) {
+        return color;
+    }
+
+    // Zones:
+    //  - RED   ≈ 0.0 / 1.0
+    //  - GREEN ≈ 0.33
+    //  - BLUE  ≈ 0.66
+    BOOL isRed   = (h < 0.05f || h > 0.95f);
+    BOOL isGreen = (h > 0.25f && h < 0.45f);
+    BOOL isBlue  = (h > 0.55f && h < 0.75f);
+
+    CGFloat hueShift      = 0.0f;
+    CGFloat satBoost      = 0.0f;
+    CGFloat brightnessAdd = 0.0f;
+
+    if (isRed) {
+        // systemRed → nudge toward orange/yellow, slightly brighter, modest sat
+        hueShift      =  0.08f * amount;  // towards yellow
+        satBoost      =  0.10f * amount;
+        brightnessAdd =  0.18f * amount;
+    }
+    else if (isGreen) {
+        // systemGreen → nudge toward yellow-green, clearly brighter + more vivid
+        hueShift      = -0.08f * amount;  // toward yellow-green
+        satBoost      =  0.25f * amount;  // push harder here
+        brightnessAdd =  0.22f * amount;  // stronger lift so it’s clearly changed
+    }
+    else if (isBlue) {
+        // systemBlue → nudge toward cyan, bright + vivid
+        hueShift      = -0.06f * amount;  // toward cyan
+        satBoost      =  0.18f * amount;
+        brightnessAdd =  0.18f * amount;
+    }
+    else {
+        // Everything else: mild generic brighten + hue wobble
+        hueShift      = -0.03f * amount;
+        satBoost      =  0.15f * amount;
+        brightnessAdd =  0.18f * amount;
+    }
+
+    // Apply hue shift with wrapping
+    CGFloat newH = h + hueShift;
+    if (newH < 0.0f) newH += 1.0f;
+    if (newH > 1.0f) newH -= 1.0f;
+
+    // Brighten: constant bump + small relative lift if not already maxed
+    CGFloat newB = b + brightnessAdd + (1.0f - b) * 0.2f * amount;
+    newB = fminf(newB, 1.0f);
+
+    // Saturation boost, clamped
+    CGFloat newS = s + satBoost;
+    newS = fminf(newS, 1.0f);
+
+    return [UIColor colorWithHue:newH saturation:newS brightness:newB alpha:a];
 }
 
 @end