You’re mainly dealing with two things: tonal range and white balance.

In Photoshop, first set proper white and black points with Levels. If the histogram doesn’t reach the right side, move the white slider inward until it meets the brightest data; this makes whites look cleaner instead of dull or “dirty.” You can also move the black slider inward slightly and adjust midtones for contrast.

If the whites still look off-color, correct the color cast. Your examples suggest one image is too green and another too blue. Shift white balance away from green toward magenta, and if needed slightly toward amber or blue depending on the image. In Photoshop, Curves can help: adjust individual color channels subtly to neutralize a cast.

For shooting, the biggest improvement is to shoot RAW instead of JPEG. RAW gives much more flexibility for correcting white balance and color without degrading the image. For consistent product shots, use a gray or color reference card in the same lighting so you can set accurate color later.

Also avoid relying only on Auto or preset white balance if consistency matters; custom white balance is usually better.