Are Female Flowers Always White?

Are female flowers always white? My girls hit stage 3 a few weeks ago and I expected all white flowers. Instead I got a liitle purple and some light reddish brown mixed in. Of my 3 girls one has the multi-color flowers and the others are all white, Is this a problem or no big deal. My concern is that this will make it more difficult to detemine peak maturity and harvest time.

It might be important to mention that the colorful plant had to be treated for Phosphorous deficiency 2 weeks ago.

different strains of pot have different coloured buds .... also the cold weather can turn the buds purple

Thanks for the input, you may be right on the money. The last 4 or 5 nights have been in the 50s and days anre low 70s, quite unseasonably cool. Thx again.

im lowering my thermostat........lol