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Documentation for GNU Taler components, APIs and protocols
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090-branding.rst (8906B)


      1 DD 90: Branding Guidelines
      2 ##########################
      3 
      4 :Design status: Accepted
      5 :Implementation status: Prototype
      6 :DD shepherd: TBD
      7 :Historical contributors: Vlada Svirsh
      8 :First published: 2026-03-07
      9 :Last substantive change: 2026-04-21
     10 :Implementation evidence: ``taler-typescript-core`` (2026-08-05, not merged into the reviewed HEAD)
     11 
     12 Summary
     13 =======
     14 This document defines visual and UX guidelines for Taler payment pages/components to give user a consistent experience
     15 across different implementations and platforms.
     16 
     17 Motivation
     18 ==========
     19 Make Taler QR code pages/components recognizable and consistent to increase user trust and confidence when using Taler.
     20 A consistent payment components also reduce user hesitation and makes troubleshooting easier.
     21 Provide guidelines for logo usage and provide main colors to be used.
     22 
     23 Requirements
     24 ============
     25 
     26 Proposed Solution
     27 =================
     28 
     29 Logo
     30 ~~~~
     31 The Taler logo is the most recognizable visual element of the brand and must be used consistently across all products,
     32 websites, documents, and payment-related screens. This section defines the approved logo versions, when each version
     33 should be used, and the rules that protect the logo’s visibility and integrity.
     34 
     35 Primary Logo (Light Mode)
     36 -------------------------
     37 The primary logo is the default Taler logo version and should be used on light backgrounds whenever possible.
     38 It is the preferred option for websites, wallet screens, documentation, printed materials etc. with a white or very light surface.
     39 
     40 This version should always appear with sufficient contrast against the background so that all logo elements remain clearly visible.
     41 It must be reproduced exactly as provided in the official assets, without modification to its colors, proportions, or internal spacing.
     42 
     43 .. image:: wallet-designs/taler-logo-light.png
     44    :alt: Taler Logo - Light Mode
     45    :width: 50%
     46 
     47 Download logo for light mode: :download:`PNG <wallet-designs/taler-logo-light.png>`, :download:`SVG <wallet-designs/taler-logo-light.svg>`
     48 
     49 Logo for Dark Mode
     50 ------------------
     51 The dark mode logo is a dedicated version of the Taler logo optimized for dark backgrounds. It should be used in wallet dark theme screens,
     52 dark websites, dark presentation slides, and any surface where the primary light-mode logo would lose visibility or contrast.
     53 
     54 Download logo for dark mode: :download:`PNG <wallet-designs/taler-logo-dark.png>`, :download:`SVG <wallet-designs/taler-logo-dark.svg>`
     55 
     56 Incorrect usage examples
     57 ------------------------
     58 The Taler logo must always appear in its approved form. Any distortion or reinterpretation weakens the identity and creates inconsistency across products.
     59 
     60 The following uses are not allowed:
     61 
     62 - changing the logo colors outside approved variants
     63 - placing the light-mode logo on a light background with poor contrast
     64 - placing the dark-mode logo on additional background
     65 - stretching, compressing, or otherwise distorting the proportions
     66 - rotating the logo
     67 - adding shadows, outlines, gradients, or glow effects
     68 - rearranging the logo symbol and wordmark
     69 - placing the logo on visually busy backgrounds that reduce readability
     70 - cropping the logo
     71 
     72 Every implementation should use the original source files supplied by the Taler design assets. When in doubt,
     73 choose the version that gives the highest contrast and clearest presentation while preserving the official logo artwork.
     74 
     75 
     76 Colors
     77 ~~~~~~
     78 The Taler color system defines the visual foundation of the brand across product interfaces, websites, documentation,
     79 and payment-related screens. Colors should support clarity, trust, accessibility, and consistency. This section identifies
     80 the main brand colors that represent Taler visually, as well as secondary colors used to support interface design and communication.
     81 
     82 Primary colors
     83 --------------
     84 
     85 The primary color should be used on light backgrounds for the most important brand and interface elements, such as primary actions,
     86 highlights, and key visual accents.
     87 
     88 .. raw:: html
     89 
     90           <code>#0042b3</code> <div style="display:inline-block;width:14px;height:14px;
     91           background:#0042b3;border:1px solid #aaa;margin-left:6px;vertical-align:middle;"></div>
     92 
     93 
     94 The dark primary color should be used in dark mode interfaces, where the default primary color would not provide the desired
     95 visual balance or contrast.
     96 
     97 .. raw:: html
     98 
     99           <code>#b4c5ff</code> <div style="display:inline-block;width:14px;height:14px;
    100           background:#b4c5ff;border:1px solid #aaa;margin-left:6px;vertical-align:middle;"></div>
    101 
    102 Secondary colors
    103 ----------------
    104 
    105 The secondary color supports the primary color and can be used for less prominent accents, supporting interface elements,
    106 and complementary highlights.
    107 
    108 .. raw:: html
    109 
    110           <code>#586a88</code> <div style="display:inline-block;width:14px;height:14px;
    111           background:#586a88;border:1px solid #aaa;margin-left:6px;vertical-align:middle;"></div>
    112 
    113 The dark secondary color should be used in dark mode where the standard secondary color is not suitable.
    114 
    115 .. raw:: html
    116 
    117           <code>#a4c9ff</code> <div style="display:inline-block;width:14px;height:14px;
    118           background:#a4c9ff;border:1px solid #aaa;margin-left:6px;vertical-align:middle;"></div>
    119 
    120 
    121 Additional color definitions
    122 ----------------------------
    123 
    124 Detailed color values and any future extensions of the palette are available here: :doc:`Color scheme <066-wallet-color-scheme>`.
    125 
    126 .. _payment-qr:
    127 
    128 Payment QR code design
    129 ~~~~~~~~~~~~~~~~~~~~~~
    130 
    131 .. image:: wallet-designs/payment-qr.png
    132    :alt: Taler QR code component design
    133    :width: 50%
    134 
    135 The payment QR code is displayed inside a dedicated rounded frame that occupies ``100%`` of the component size.
    136 This frame defines the full visible area of the QR payment element and serves as the main reference for all internal proportions.
    137 
    138 The frame uses the color ``#F1F1F4``. Inside the frame, the QR code itself is rendered on a white background to preserve maximum
    139 contrast and scanning reliability.
    140 
    141 Frame
    142 -----
    143 The QR payment component uses a rounded rectangular frame with the following properties:
    144 
    145 - frame size: ``100%``
    146 - frame background color: ``#F1F1F4``
    147 - frame shape: rounded rectangle
    148 - frame corner radius: ``8%`` relative to the frame size
    149 
    150 
    151 QR code
    152 -------
    153 .. image:: wallet-designs/payment-qr-1.png
    154    :alt: Taler QR code design
    155    :width: 50%
    156 
    157 The QR code is centered inside the frame and occupies ``87.5%`` of the frame size.
    158 
    159 The QR code must always use:
    160 - white background
    161 - black QR modules
    162 - centered placement inside the frame
    163 
    164 The QR code background must remain white even though the surrounding frame uses ``#F1F1F4``. This separation ensures good readability and reliable scanning.
    165 
    166 Animated lines
    167 --------------
    168 
    169 Two animated lines move clockwise along the outer edge of the QR code frame as a subtle branded accent.
    170 The animation adds a sense of activity and visual focus while keeping the QR code itself visually stable and easy to scan.
    171 
    172 The animated lines have the following properties:
    173 
    174 - direction: clockwise
    175 - stroke width: ``2.6%`` relative to the frame size
    176 - line height: ``57%`` relative to the frame size
    177 - color: linear gradient from ``#F1F1F4`` to ``#0042B3`` to ``#F1F1F4``
    178 - placement: along the inner edge of the frame, between the frame border and the QR code area
    179 
    180 Logo inside the QR code
    181 -----------------------
    182 .. image:: wallet-designs/payment-qr-2.png
    183    :alt: Taler logo placement inside QR code
    184    :width: 50%
    185 
    186 The Taler logo is placed in the center of the QR code. The logo must always appear together with its dedicated white
    187 background shape so that it remains visually separated from the QR modules behind it.
    188 
    189 The approved asset for this usage is available here: :download:`PNG <wallet-designs/qr-logo.png>`, :download:`SVG <wallet-designs/qr-logo.svg>`.
    190 
    191 The total height of the logo together with its white background is ``12.5%`` relative to the frame size.
    192 
    193 The logo treatment must always follow these rules:
    194 - the logo is centered inside the QR code
    195 - the logo always includes the white background
    196 - the logo background must match the white QR background
    197 - the logo must not be recreated manually
    198 - only the approved asset may be used
    199 
    200 Size summary
    201 ------------
    202 
    203 The payment QR component uses the following proportions:
    204 
    205 - frame size: ``100%``
    206 - QR code size: ``87.5%``
    207 - animation width: ``2.6%``
    208 - logo with background height: ``12.5%``
    209 
    210 
    211 
    212 Test Plan
    213 =========
    214 
    215 (If this DD concerns a new or changed feature, describe how it can be tested.)
    216 
    217 Definition of Done
    218 ==================
    219 
    220 (Only applicable to design documents that describe a new feature.  While the
    221 DoD is not satisfied yet, a user-facing feature **must** be behind a feature
    222 flag or dev-mode flag.)
    223 
    224 Alternatives
    225 ============
    226 
    227 Drawbacks
    228 =========
    229 
    230 Discussion / Q&A
    231 ================
    232 
    233 (This should be filled in with results from discussions on mailing lists / personal communication.)