Strapless bra for a white halterneck top

[Mystical1981]

What strapless bra do you all wear under a white top? I'm out this weekend and I have brought a nice white halterneck top. I brought a nude underwired strapless bra from primark but it looks bad under the top the cups looks weird shape like 2 saucers. I need a strapless bra that doesn't look a weird shape, doesnt show under a white top and preferably seamless.

Any ideas?
Thankyou

I wear a halterneck bra instead because I don't find strapless bras look 'right' on me Zekeylin Low Back Bras-Lightly Lined Seamless Invisible Backless Bra-Underwire Multiway Convertible Low Cut Halter Bra (Sand, 34DD) : Amazon.co.uk: Fashion

Red doesn’t show under white

What size do you need? The M&S white non padded for larger boobs is amazing. No idea why they stopped the black one and why larger boobs need padding is beyond me so this one is fabulous.

https://www.marksandspencer.com/embrace-embroidered-underwired-strapless-bra-f-h/p/clp60451339?intid=mobile_app_pdp_share