https://monochrome-watches.com/tudor-heritage-1970s-chronographs-tudor-heritage-chrono/

The first chronographs by Tudor only appeared in 1970. As children of the “Seventies”, these early chronographs were designed accordingly to the slightly psychedelic feel that was going on at that time: bold shapes, massive cases, graphic lines and bright colors were the key inspirations. Two generations represent these early days of Tudor chronographs, the 70xx series and the 71xx series, both great sources of inspiration for the watch that is now known as the Tudor Heritage Chrono.

...

In 2013, Tudor introduced a second version of the Tudor Heritage Chrono 70330, this time finding inspiration in the second-generation of Oysterdate chronographs, with the Montecarlo 7169/0 in sight. The new Tudor Heritage Chrono Blue 70330B is based on the same visual and technical architecture as the Grey and Black versions, sharing case, movement, bracelet and bidirectional bezel with 12-hour scale. However, its dial is a strong tribute to the Montecarlo versions. First of all, it reintroduces the bright and catchy blue colour scheme, with light grey central part and orange accents (minute scale, sub-dual and second-hand). Just like the dial of the 7033 evolved to become the dial of the 7169, the Heritage Chrono Blue features a different type of dial, with rectangular markers, different sub-dial track (more colorful, with more sub-divisions) and some straight hands.

Once again here, just like with the Black Bay, Tudor did a superb job by bringing back the vintage flair of the 1970s, without making a watch that feels outdated. These watches are modern, while retaining the known codes of the brand, and the colours that made the ancestors so appreciated by collectors.