* include/freetype/config/ftheader.h (FT_COLOR_H): New macro.
* include/freetype/internal/ftobjs.h (FT_Colr_Internal): Change
type of `load_flags' to `FT_Int32'.
* include/freetype/internal/sfnt.h (TT_Load_Colr_Layer_Func): Change
type of `idx' to `FT_UInt'.
(TT_Blend_Colr_Func): Change type of `color_index' to `FT_UInt'.
* src/base/ftobjs.c (FT_Render_Glyph_Internal): Change type of
`load_flags' to `FT_Int32'.
* src/sfnt/ttcolr.c (find_base_glyph_record,
tt_face_load_colr_layers): Change type of `glyph_id' to `FT_UInt'.
(tt_face_find_color, tt_face_colr_blend_layer): Change type of
`color_index' to `FT_UInt'.
Fix signedness and type issues.
* src/sfnt/ttcolr.h: Updated.