--- a/src/blitter/32bpp_anim.cpp
+++ b/src/blitter/32bpp_anim.cpp
@@ -161,16 +161,16 @@
 						do {
 							/* Compiler assumes pointer aliasing, can't optimise this on its own */
 							uint m = *src_n++;
-							/* Above 217 is palette animation */
+							/* Above 217 (PALETTE_ANIM_SIZE_START) is palette animation */
 							*anim++ = m;
-							*dst++ = (m >= 217) ? this->LookupColourInPalette(m) : *src_px;
+							*dst++ = (m >= PALETTE_ANIM_SIZE_START) ? this->LookupColourInPalette(m) : *src_px;
 							src_px++;
 						} while (--n != 0);
 					} else {
 						do {
 							uint m = *src_n++;
 							*anim++ = m;
-							if (m >= 217) {
+							if (m >= PALETTE_ANIM_SIZE_START) {
 								*dst = ComposeColourPANoCheck(this->LookupColourInPalette(m), src_px->a, *dst);
 							} else {
 								*dst = ComposeColourRGBANoCheck(src_px->r, src_px->g, src_px->b, src_px->a, *dst);
@@ -327,7 +327,7 @@
 	}
 
 	/* We update the palette (or the pixels that do animation) immediatly, to avoid graphical glitches */
-	this->PaletteAnimate(217, _use_dos_palette ? 38 : 28);
+	this->PaletteAnimate(PALETTE_ANIM_SIZE_START, _use_dos_palette ? PALETTE_ANIM_SIZE_DOS : PALETTE_ANIM_SIZE_WIN);
 }
 
 void Blitter_32bppAnim::CopyToBuffer(const void *video, void *dst, int width, int height)

--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -997,8 +997,8 @@
 	 * A few more for the DOS palette, because the water colors are
 	 * 245-254 for DOS and 217-226 for Windows.  */
 	const ExtraPaletteValues *ev = &_extra_palette_values;
-	int c = _use_dos_palette ? 38 : 28;
-	Colour old_val[38];
+	int c = _use_dos_palette ? PALETTE_ANIM_SIZE_DOS : PALETTE_ANIM_SIZE_WIN;
+	Colour old_val[PALETTE_ANIM_SIZE_DOS];
 	uint i;
 	uint j;
 	uint old_tc = _palette_animation_counter;
@@ -1007,7 +1007,7 @@
 		_palette_animation_counter = 0;
 	}
 
-	d = &_cur_palette[217];
+	d = &_cur_palette[PALETTE_ANIM_SIZE_START];
 	memcpy(old_val, d, c * sizeof(*old_val));
 
 	/* Dark blue water */
@@ -1101,8 +1101,8 @@
 	if (blitter != NULL && blitter->UsePaletteAnimation() == Blitter::PALETTE_ANIMATION_NONE) {
 		_palette_animation_counter = old_tc;
 	} else {
-		if (memcmp(old_val, &_cur_palette[217], c * sizeof(*old_val)) != 0) {
-			_pal_first_dirty = 217;
+		if (memcmp(old_val, &_cur_palette[PALETTE_ANIM_SIZE_START], c * sizeof(*old_val)) != 0) {
+			_pal_first_dirty = PALETTE_ANIM_SIZE_START;
 			_pal_count_dirty = c;
 		}
 	}

--- a/src/gfx_type.h
+++ b/src/gfx_type.h
@@ -191,7 +191,7 @@
 	COLOUR_GREY,
 	COLOUR_WHITE,
 	COLOUR_END,
-	INVALID_COLOUR = 0xFF
+	INVALID_COLOUR = 0xFF,
 };
 
 /** Colour of the strings, see _string_colormap in table/palettes.h or docs/ottd-colourtext-palette.png */
@@ -216,6 +216,13 @@
 	TC_BLACK       = 0x10,
 };
 
+/** Defines a few values that are related to animations using palette changes */
+enum PaletteAnimationSizes {
+	PALETTE_ANIM_SIZE_WIN   = 28,   ///< number of animated colours in Windows palette
+	PALETTE_ANIM_SIZE_DOS   = 38,   ///< number of animated colours in DOS palette
+	PALETTE_ANIM_SIZE_START = 217,  ///< Index in  the _palettes array from which all animations are taking places (table/palettes.h)
+};
+
 enum StringColorFlags {
 	IS_PALETTE_COLOR = 0x100, ///< color value is already a real palette color index, not an index of a StringColor
 };