Denshi Jisho — Online Japanese dictionary

真っ赤 まっか 1: bright red; deep red; flushed (of face);
2: (Na-adjective) downright (e.g. lie); complete; utter
Common word, Na-adjective, Noun 

You can also

Look up kanji details for 真っ赤.

Try a Yahoo Jisho search for 真っ赤 .
Try a Goo Jisho search for 真っ赤 .
Try a Google search for 真っ赤 .