For white-colored AM4 motherboards, AFAIK, there are only two choices: one is an ATX-sized (the
MSI B350 Tomahawk Arctic), the other one is mATX-sized (the
MSI B350M Mortar Arctic). Both white motherboards, however, only have white LED ambient lighting.
There's one titanium-colored ("dirty white") ATX-sized (the
MSI X370 Xpower Gaming Titanium) but costs way above your budget.
For black-colored/gray-colored AM4 motherboards with white accents, there are seven motherboards to choose from: the
Asrock X370 Taichi (with RGB lighting, but costs above your budget), the
Asrock X370 Killer SLI (with RGB lighting, costs above your budget), the
Asrock X370 Killer SLI/ac (with RGB lighting being offered at ~$140 now in Newegg), the
MSI X370 Krait Gaming (with white ambient lighting, but you might find the look not pleasing), the
MSI B350 Krait Gaming (with white ambient lighting, but you also might find the look not pleasing), the
Asrock AB350 Pro4 (with no LED lighting, but might find the "Pro" text unappealing), and the
Asrock AB350M Pro4 (with no LED lighting, and also just an mATX size mobo).
There are no blue-colored AM4 motherboards, AFAIK.
Considering your want a white-black themed AM4 ATX motherboard with RGB lighting for under $150, the above choices only boils down to the
Asrock X370 Killer SLI/ac:
PCPartPicker part list /
Price breakdown by merchant
Motherboard: ASRock - X370 KILLER SLI/ac ATX AM4 Motherboard ($138.98 @ Newegg)
Total: $138.98
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-07-27 01:28 EDT-0400