Remember a while back when we covered how some people were (and still are) experiencing issues with colours on their devices after updating to Nodo? We even put in a small work around fix which required unlocking the device, unfortunately. Still, people are (and rightfully so) aggravated that images and especially gradients don't look as good as they once did.
A thread on the Microsoft forums has been slowly accumalating posts, which have been joined by a response from a Moderator and member of technical support, Aled T:
When HTC launched the HD7 and Trophy they upgraded the color depth to 32 bit, which was outside of Microsoft’s design requirements of 16bit. Microsoft implemented the design standards to help ensure the best possible and consistent experience for all customers on all Windows Phones. To continue to deliver a stable and consistent customer experience, HTC returned the devices to the 16 bit design requirements as part of the March (7.0.7390) update.
The color palette change should not make a noticeable change to most customers experience on their Windows Phone 7. Microsoft's goal is to ensure that the device is performing as optimally as possible – and as always their engineering teams continue to investigate the opportunities for future improvements.
We should remember though, back at MIX '11 we were told that Mango will address this and full 32-bit will be coming. Makes sense that the HTC devices are brought back to a reliable level until the OS is updated for improvements to be made backend. While we understand this is frustrating for most (due to Metro UI supposedly being the "sexier" interface on the market), like the current state of the updates, 32-bit will be "coming soon". Hang in until Mango, seems like it'll be a blast.