This　paper　designs　and　analyzes　the　bit-interleaved　coded　modulation　with　iterative　demapping　and　decoding　(BICM-ID)　framework　under　color-shift-keying　(CSK)　modulation　to　achieve　spectrally　efficient　transmissions　in　visible　light　communication　(VLC)　systems.　Specifically,　we　investigate　the　protograph　low-density　parity-check　(LDPC)　codes,　bit-to-symbol　mapping　schemes,　and　constellation　labeling　rules　in　higher-order　CSK-aided　VLC　systems.　To　fully　explore　the　BICM-ID　benefit,　we　propose　an　irregular　CSK　mapping,　in　which　an　M-ary　standardized　constellation　(called　＇Standard　constellation＇)　and　a　new　M-ary　constellation　(called　＇Target　constellation＇)　are　separately　applied　to　modulate　two　different　coded　sub-blocks　in　a　codeword　to　optimize　the　error　performance　of　the　CSK-aided　VLC　systems.　Furthermore,　using　a　modified　protograph　extrinsic　information　transfer　(PEXIT)　algorithm,　we　construct　two　types　of　protograph　LDPC　codes　(i.e.,　unpunctured　and　punctured　protograph　LDPC　codes)　that　outperform　the　conventional　protograph　LDPC　codes.　Both　analytical　and　simulation　results　show　that　the　proposed　irregular-CSK-mapped　BICM-ID　employing　the　new　protograph　LDPC　codes　and　Target　constellation　is　capable　of　achieving　outstanding　performance,　and　is　a　promising　transmission　solution　for　high-speed　VLC　applications.　©　1967-2012　IEEE.