Looks very much like phosphorus deficient.
Hmm
Also has hints of magnesium I'll admit.
Magnesium is essential for photosynthesis, it is needed for the absorption of other vital nutrients. Especiall phosphorus. Magnesium is a carrier for phosphorus within plants.
pH of your root zone may not be in the correct range, your cannabis cannot properly absorb magnesium through the roots. Often with this deficiency, the magnesium is present, but the roots cannot absorb the magnesium properly due to an improper pH.
First you need to check as magnesium will have problems above 7 and below 5.