redden

verbs

turn red, as if in embarrassment or shame
"The girl blushed when a young man whistled as she walked by"
blush, crimson, flush, redden
make red
"The setting sun reddened the sky"
redden
is a type of (narrower)
add color to
"The child colored the drawings"; "Fall colored the trees"; "colorize black and white film"
color, color in, colorise, colorize, colour, colour in, colourise, colourize
turn red or redder
"The sky reddened"
redden
is a type of (narrower)
change color, often in an undesired manner
"The shirts discolored"
color, colour, discolor, discolour