diff --git a/Userland/Libraries/LibGfx/ICC/Profile.cpp b/Userland/Libraries/LibGfx/ICC/Profile.cpp
index ebef73ded5..1cc07743a6 100644
--- a/Userland/Libraries/LibGfx/ICC/Profile.cpp
+++ b/Userland/Libraries/LibGfx/ICC/Profile.cpp
@@ -1227,7 +1227,7 @@ ErrorOr<FloatVector3> Profile::to_pcs_a_to_b(TagData const& tag_data, ReadonlyBy
         if (a_to_b.number_of_output_channels() != number_of_components_in_color_space(connection_space()))
             return Error::from_string_literal("ICC::Profile::to_pcs_a_to_b: mAB output channel count does not match profile connection space size");
 
-        return a_to_b.evaluate(color);
+        return a_to_b.evaluate(connection_space(), color);
     }
     }
     VERIFY_NOT_REACHED();
diff --git a/Userland/Libraries/LibGfx/ICC/TagTypes.h b/Userland/Libraries/LibGfx/ICC/TagTypes.h
index c601383e42..6a82611047 100644
--- a/Userland/Libraries/LibGfx/ICC/TagTypes.h
+++ b/Userland/Libraries/LibGfx/ICC/TagTypes.h
@@ -448,7 +448,7 @@ public:
     Vector<LutCurveType> const& b_curves() const { return m_b_curves; }
 
     // Returns the result of the LUT pipeline for u8 inputs.
-    ErrorOr<FloatVector3> evaluate(ReadonlyBytes) const;
+    ErrorOr<FloatVector3> evaluate(ColorSpace connection_space, ReadonlyBytes) const;
 
 private:
     u8 m_number_of_input_channels;
@@ -1023,8 +1023,9 @@ private:
     Vector<XYZ, 1> m_xyzs;
 };
 
-inline ErrorOr<FloatVector3> LutAToBTagData::evaluate(ReadonlyBytes color_u8) const
+inline ErrorOr<FloatVector3> LutAToBTagData::evaluate(ColorSpace connection_space, ReadonlyBytes color_u8) const
 {
+    VERIFY(connection_space == ColorSpace::PCSXYZ || connection_space == ColorSpace::PCSLAB);
     VERIFY(number_of_input_channels() == color_u8.size());
     VERIFY(number_of_output_channels() == 3);
 
@@ -1032,6 +1033,15 @@ inline ErrorOr<FloatVector3> LutAToBTagData::evaluate(ReadonlyBytes color_u8) co
     // "Data are processed using these elements via the following sequence:
     //  (“A” curves) ⇨ (multi-dimensional lookup table, CLUT) ⇨ (“M” curves) ⇨ (matrix) ⇨ (“B” curves).
 
+    // "The domain and range of the A and B curves and CLUT are defined to consist of all real numbers between 0,0 and 1,0 inclusive.
+    //  The first entry is located at 0,0, the last entry at 1,0, and intermediate entries are uniformly spaced using an increment of 1,0/(m-1).
+    //  For the A and B curves, m is the number of entries in the table. For the CLUT, m is the number of grid points along each dimension.
+    //  Since the domain and range of the tables are 0,0 to 1,0 it is necessary to convert all device values and PCSLAB values to this numeric range.
+    //  It shall be assumed that the maximum value in each case is set to 1,0 and the minimum value to 0,0 and all intermediate values are
+    //  linearly scaled accordingly."
+    // Scaling from the full range to 0..1 before a curve and then back after the curve only to scale to 0..1 again before the next curve is a no-op,
+    // so we only scale back to the full range at the very end of this function.
+
     auto evaluate_curve = [](LutCurveType const& curve, float f) {
         VERIFY(curve->type() == CurveTagData::Type || curve->type() == ParametricCurveTagData::Type);
         if (curve->type() == CurveTagData::Type)
@@ -1087,27 +1097,29 @@ inline ErrorOr<FloatVector3> LutAToBTagData::evaluate(ReadonlyBytes color_u8) co
             (float)e[3] * color[0] + (float)e[4] * color[1] + (float)e[5] * color[2] + (float)e[10],
             (float)e[6] * color[0] + (float)e[7] * color[1] + (float)e[8] * color[2] + (float)e[11]
         };
-
-        // Mystery conversion factor!
-        // skcms, littlecms, and argyll all do this somewhere, but I don't understand why!
-        // skcms has a "TODO: understand" comment as well.
-        // littlecms and argyll have both comments which don't make sense to me.
-        // littlecms does this to the matrix profile matrices (i.e. it considers the lut pcs scale canonical).
-        // skcms does it to the mAB matrix (...which means it'll do something different if the matrix is missing,
-        //     and it'll also do something different if the b curve isn't the identity).
-        // argyll does it in Lut_Lut2XYZ(), but I'm not clear on when that's called.
-        // SampleICC does it in IccCmm.cpp, XYZScale() and in IccUtil.cpp, icXyzFromPcs().
-        // Without this, colors are too bright. So let's do it too, and maybe I'll understand it one day.
-        new_color *= 65535 / 32768.f; // ???
-
         color = new_color.clamped(0.f, 1.f);
     }
 
-    return FloatVector3 {
+    FloatVector3 output_color {
         evaluate_curve(m_b_curves[0], color[0]),
         evaluate_curve(m_b_curves[1], color[1]),
         evaluate_curve(m_b_curves[2], color[2])
     };
+
+    // ICC v4, 6.3.4.2 General PCS encoding
+    if (connection_space == ColorSpace::PCSXYZ) {
+        // Table 11 - PCSXYZ X, Y or Z encoding
+        output_color *= 65535 / 32768.0f;
+    } else {
+        VERIFY(connection_space == ColorSpace::PCSLAB);
+        // Table 12 — PCSLAB L* encoding
+        output_color[0] *= 100.0f;
+
+        // Table 13 — PCSLAB a* or PCSLAB b* encoding
+        output_color[1] = output_color[1] * 255.0f - 128.0f;
+        output_color[2] = output_color[2] * 255.0f - 128.0f;
+    }
+    return output_color;
 }
 
 }