Yes—adding a simple red overlay can help a little, but it’s usually a blunt fix. A better post-processing approach is to correct white balance and color balance rather than just laying red over the image.

If you shot RAW, start with white balance: use a gray/neutral picker if there’s anything neutral in the frame, or manually adjust temperature and tint. This usually gives more natural results than a red layer alone.

For JPEGs, curves or color balance tools can work, but you have less flexibility than with RAW.

In Photoshop, the Photo Filter adjustment is a good quick option because it simulates real warming/cooling filters. Try a warming filter and adjust density; you can stack adjustments if needed. If the blue cast is very strong, first reduce it with color balance or white balance, then fine-tune with a warming/photo filter.

For future dives, physical underwater color-correction filters in front of the lens are preferable to fixing everything later, because they improve white balance at capture and help the camera record better channel data.