Unknown Strain need diagnosis (Pictures)

Unknown strains
Outdoor grow
Unknown start date of flowering maybe 3 Weeks into flowering
FFOF medium, having to water daily sometimes every other day
No nutes during veg. Started bloom nutes when I noticed flowering 1 week half strength. Tips burned a little but leaves still yellowing. 2nd week full strength nutes. burnt tips remained the same. 3rd week full strength nutes. Waiting to see if I notice yellowing leaves slow down (FoxFarm nutes)
Purple limbs and/or branches as well.
What can I give to help stop yellowing but not give too much nitrogen at the same time.
I don't want to over nute the plant as I did not give nutes during veg.

Thanks for any advice

It looks like a nitrogen deficiency to me.. Maybe give it a little kelp. Plants do still require some nitrogen during flower, just not as much as veg. So your plant probably used up all the nitrogen in the soil during veg. Do your bloom nutes have any nitrogen at all?

And it looks like it needs more light.

I'd be careful with the nutes since you said you've hot it full strength.
I wouldn't use anything stronger than seaweed (kelp) as previously suggested. Just start using a flowering nutes and a little seaweed. You'll be good.
Yellowing is normal at that stage of flower