My Lavender Orpingtons are 24 weeks and haven't started laying.

[Savannah Rose]

Their crest and waddles are quite red (except parts by their ears are still pale) and the weather here has been nice. There has been less daylight though. Could it be nutrition or are they just not ready yet?

 

[Rod-T]

Give it more time.. I'd put light in coop set by timer to come on early .the need 14 hrs of daylight

 

[aart]

Their crest and waddles are quite red (except parts by their ears are still pale) and the weather here has been nice. There has been less daylight though. Could it be nutrition or are they just not ready yet?

24 or more weeks isn't unusual for some birds, and coming into POL at this time of year can slow things down.
I'd just be patient.

You could use lights, but that takes time to implement.
Here's a pretty good article on supplemental lighting.

Check their pelvic points too.

Signs of onset of lay---I've found the pelvic points to be the most accurate.
Squatting:
If you touch their back they will hunker down on the ground, then shake their tail feathers when they get back up.
This shows they are sexually mature and egg laying is close at hand.

Combs and Wattles:
Plump, shiny red - usually means laying.
Shriveled, dryish looking and pale - usually means not laying.
Tho I have found that the combs and wattles can look full and red one minute then pale back out the next due to exertion or excitement, can drive ya nuts when waiting for a pullet to lay!

2 bony points(pelvic bones) on either side of vent:
Less than 2 fingertip widths apart usually means not laying.
More than 2 fingertip widths apart usually means laying.