Fixed color lightening changing hue, as well as add screen color blending mode

src/math.ts

@@ -178,11 +178,19 @@ export class Color {
 	}
 
 	lighten(a: number): Color {
-		return new Color(this.r + a, this.g + a, this.b + a)
+		return new Color(
+			(255 - this.r) * a + this.r,
+			(255 - this.g) * a + this.g,
+			(255 - this.b) * a + this.b
+		)
 	}
 
 	darken(a: number): Color {
-		return this.lighten(-a)
+		return new Color(
+			this.r * (1-a),
+			this.g * (1-a),
+			this.b * (1-a)
+		)
 	}
 
 	invert(): Color {
@@ -196,6 +204,14 @@ export class Color {
 			this.b * other.b / 255,
 		)
 	}
+
+	screen(other: Color): Color {
+		return new Color(
+			255 - (255-this.r) * (255-other.r) / 255,
+			255 - (255-this.g) * (255-other.g) / 255,
+			255 - (255-this.b) * (255-other.b) / 255,
+		)
+	}
 
 	eq(other: Color): boolean {
 		return this.r === other.r

src/types.ts

@@ -3247,16 +3247,43 @@ export declare class Color {
 	static WHITE: Color
 	static BLACK: Color
 	clone(): Color
+
 	/**
-	 * Lighten the color (adds RGB by n).
+	 * Lighten color by a certain percentage
+	 * @param percent Number between 0-1 indicating how light to make color
+	 * @example
+	 * color.lighten(0); // Does nothing
+	 * color.lighten(0.5); // 50% lighter
+	 * color.lighten(1); // White
+	 * @returns Lightened color
 	 */
-	lighten(n: number): Color
+	lighten(percent: number): Color
 	/**
-	 * Darkens the color (subtracts RGB by n).
+	 * Darken color by a certain percentage
+	 * @param percent Number between 0-1 indicating how dark to make color
+	 * @example
+	 * color.darken(0); // Does nothing
+	 * color.darken(0.5); // 50% darker
+	 * color.darken(1); // Black
+	 * @returns Darkened color
 	 */
-	darken(n: number): Color
+	darken(percent: number): Color
 	invert(): Color
+
+	/**
+	 * Apply multiply blend mode on color
+	 * @param other Color to blend with
+	 * @returns Result of blended colors
+	 */
 	mult(other: Color): Color
+
+	/**
+	 * Apply screen blend mode on color
+	 * @param other Color to blend with
+	 * @returns Result of blended colors
+	 */
+	screen(other: Color): Color
+
 	eq(c: Color): boolean
 	toString(): string
 }