I have yet to see light blue yarn on clearance, and if I found a thrift sweater in icy blue, I'd wear it.
But maybe you have some to overdye.
What can you expect?
A. Yellow McCormick = lemon cough drop
B. Red McCormick = bubble gum pink
C. Blue McCormick = faded blue jeans
D. Green McCormick = very bright leaf
E. Neon Purple McCormick = grape bubble gum
F. Neon Pink McCormick = watermelon bubble gum
G. Neon Blue McCormick = cornflower
H. Neon Green McCormick = Easter grass
I. Blue Wilton = deco blue
J. Brown Wilton = burnt sienna
K. Burgundy Wilton = dark blush
L. Copper Wilton = pumpkin
M. Gold Wilton = jasmine
N. Kelly Wilton = kelly
O. Lemon Wilton = rain slicker
P. No Taste Red Wilton = pink
Q. Red Wilton = bittersweet
R. Sky Wilton = sky
S. Violet Wilton = purple people eater
T. Yellow Wilton = lemon cough drop
U. Lemon-Lime Kool-Aid = celery
V. Black Cherry Kool-Aid = maple leaf
W. Strawberry Kool-Aid = lipstick
X. Grape Kool-Aid = violet
Y. Berry Blue Kool-Aid = sky
Z. Orange Kool-Aid = orange
Samples are 1 yard of Lion Brand Fishermen's wool.
The amount of food color in each dye bath was 1 drop McCormick, a trace of Wilton coating a toothpick or 1 tablespoon dilution of Kool-Aid (1 packet Kool-Aid to 8 ounces water).
The samples were soaked in the dyebath for a full day before heating.
Notes on why to overdye light blue yarn:
Overdyeing light blue yarn is… chancy.
A blue this pale didn't change the McCormick or the Kool-Aid much.
Of course, if I wanted this yarn as a substitute for white yarn, then that would be fine.
Sample K, the Wilton burgundy is nice - a warm pink without being too obnoxious.