Could I do microneedling RF with tanned skin? Or is it better to do it without tanned skin. Need to get this done in the summer

Having RF Microneedling with tanned skin is safe. We do advise though to stay out of the sun 1 week before and after the treatment and to of course, use great physical sunblock everyday, especially post treatment. 
*It is not safe to microneedle over spray tan, bronzer or items with pigment, as it can tattoo pigment into the dermal layer.
-Have fun, we love microneedling

If your skin is already tan, there's no contraindication to doing micro-needle radiofrequency. However, it is not recommended that you go in the sun after the treatment.Jeff Rapaport MD FAADRealself All-star

Tanning is a problem with laser work or IPL, But, not so much with tanned skin. Having said that, it is very important to stay out of the sun post treatment. You're skin will be delicate and more opt to get burned and hyper-pigmentation right after treatment. Wishing you the best from Boston, Dr. Onir

If the skin is already tanned it is okay to do microneedling. After microneedling we suggest that you stay out of the sun as the  skin that was treated with the needles may hyperpigment. Tanned skin is damaged skin. Please use sun protection.

RF is thought to be 'colour blind' especially with insulation, however some energy is delivered on the surface. This means one may still get PIH- skin colour changes, especially on tanned skin. The more superficial the treatment, the higher the chances.Microneedling RF is an extension of microneedling with ‘energy’. Generation one devices such as Dermapen/ Skin Pen etc. use needles without heat to remodel collagen. Generation Two devices are microneedles that are not insulated, hence heat is delivered along the length of needles. Examples include Secret RF and Intensif. Generation Three devices use insulated needles to deliver heat at the point of the needle. Examples include Infini RF, as well as Genius. 
Newer generation devices will generally give better outcomes, however with insulation, the safety of microneedling RF devices is usually better than generation two machines. With insulation the incidence of skin colour darkening and ‘grids’ secondary to ‘stamping’ is less, however it is largely technique dependent. 
Microneedling RF should be viewed as a tool to be incorporated in the suitable clinical context. As with most other ‘fractional technology’ 3-5 sessions spaced 3-6 weeks apart will give the best results. Be guided by your specialist.  All the best, 
Dr Davin Lim and the team at Clinic Cutis
Brisbane. Australia.