increase cach color max to 15 from 7

include/mimalloc/types.h

diff --git a/include/mimalloc/types.h b/include/mimalloc/types.h
index c3b5383..543c7da 100644
--- a/include/mimalloc/types.h
+++ b/include/mimalloc/types.h
@@ -598,7 +598,7 @@
 #define MI_PAGE_CACHE_OFFSET_MAX          (MI_PAGE_OSPAGE_BLOCK_ALIGN2 - MI_PAGE_CACHE_OFFSET_UNIT) // maximal offset (32 possible offsets)
 // Offset the first block in pages with small blocks (< 512)
 #define MI_PAGE_SMALL_CACHE_OFFSET_UNIT   (64)
-#define MI_PAGE_SMALL_CACHE_OFFSET_MAX    (7*MI_PAGE_SMALL_CACHE_OFFSET_UNIT)
+#define MI_PAGE_SMALL_CACHE_OFFSET_MAX    (15*MI_PAGE_SMALL_CACHE_OFFSET_UNIT)  // up to 1 KiB (16 offsets)
 
 // The max object sizes are intended to not waste more than ~ 12.5% internally over the page sizes.
 #define MI_SMALL_MAX_OBJ_SIZE             ((MI_SMALL_PAGE_SIZE-MI_PAGE_OSPAGE_BLOCK_ALIGN2)/6)   // = 10 KiB