4 weeks post breast implant replacement and lift. Cracking skin redness rippling and yellow spotting... (photos)

NO! Not normal. Seek in person second opinions to be sure you are healing correctly. Rule out cellulitis vs dermatitis. 

Hello Dex05-You appear to have a nice postop result in regards to shape and size. If the extra swelling of your stretch marks is the 'rippling' to which you are referring, then do not worry about it as it is very normal and will resolve with time. The redness along the inferior pole of your breasts may be related to a vascular blush reaction to the undermining of the skin in this area during surgery, which is normal, but it could also have an infectious component. If this is the case, which your surgeon will need to determine, antibiotics and a skin care regimen should be instituted. So make sure your surgeon is being kept up to date on your progress and any changes in your skin. Good luck!

The shape  and size of your breasts look very good. The skin reaction could be caused by a number of issues. Are you putting any kind of ointment(neosporin) or creams on the  skin?  You could be reacting to the ointment or  cream. Have you changed bras or had a change in the laudry soap or  fabric softener ? Try removing any possible agent that may be next to or on the skin. Cleanse the areas with non-perfumed soap and use a 100% cotton wash cloth to cover the incisions. Change these 2-3 times per day. You may apply OTC  hydrocortisone to the skin.........BEFORE YOU DO ANYTHING....consult with your plastic surgeon.