Now that we have our own supplies of the new tariff stamps previously mentioned here, I can show the actual stamps compared with the pre-issue publicity image supplied by Royal Mail, and the last use of the same colours, rescanned for comparison purposes.
£1.35 orchid mauve (previously used for £1.52)
£1.60 amber yellow (previously used for £1.33)
£2.30 gooseberry green (previously used for £1.05)
£2.80 spruce green (previously used for £2.45)
£3.45 dark pine green (previously used for £1.40)
£3.60 bright orange (the 87p was just 'orange')
So, as predicted, the £2.30 and £2.80 stamps are nothing like the publicity pictures which makes you wonder why Royal Mail can't be bothered to get it right. Who are they producing these pictures for? Not for the general press which really can't see past 1st & 2nd class rises (which is what their readers are really concerned about).
So it must be for the philatelic media and trade, in which case what is provided is useless for that target audience. As a philatelic service, Royal Mail really don't come up to scratch, not for collectors who are consistently short-changed as to what they can and can't buy from the part of the organisation previously referred to as the Philatelic Bureau. And not for dealers who get a better service, and publishers, who both deserve to have accurate information and correctly coloured pictures.
What the actual stamps do show is that the colours of all but the £2.30 and £3.45 are actually pleasantly bright.
All are printed by ISP Walsall on SBP2 paper with small text above Large, known by some as SBP2i. The phosphor is blue (I'll need darkness to tell how bright) and there is no yellow fluorescence. Last year we had reprints in February and further reprints for some values as needed. Many of these produced different variants which we hope, for the sake of collectors' pockets, is not repeated this year!
First printing dates are confirmed as
£1.35 07/01/19
£1.60 07/01/19
£2.30 08/01/19
£2.80 09/01/19
£3.45 09/01/19
£3.60 09/01/19
These are counter sheets of 25 on each primary sheet for each value, meaning a grid of 2 columns of 4 rows. As you can see the Queen's head is, as last year, the wishy-washy flat version lacking the detail shown in the publicity pictures and on earlier stamps.
The stamps will be issued at Post Office branches and from Royal Mail on Tuesday 19th March for the new rates commencing Monday 25th March. So for variety you could use some of the lower values to send airmail letters at the old rates, for example the new £1.35 + 20p to make up the European over 20g rate.
In the run up to Comic Relief Red Nose Day on 15 March, Royal Mail has unveiled a special edition ‘laughing’ postbox, which
responds to posted mail with a variety of jokes from stand-up comedian Hal Cruttenden.
From the comments: 
With the Marvel Comics stamps to be issued in a week, I have published an updated version of the checklist which includes the four new stamps from the Prestige Stamp Book, and the single 1st class from the retail booklet - the first of the M19L stamps.
